<PAGE>

                                                                  EXECUTION COPY

                                                                   EXHIBIT 10.18


      CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED BY
      BRACKETS([**]), HAS BEEN OMITTED AND FILED SEPARATELY WITH THE SECURITIES
      AND EXCHANGE COMMISSION PURSUANT TO RULE 406 OF THE SECURITIES ACT OF
      1933, AS AMENDED


                             COLLABORATION AGREEMENT

                                 BY AND BETWEEN

                                   AMGEN INC.

                                       AND

                                  VIACELL, INC.

                               DECEMBER 23, 2003


<PAGE>






                                TABLE OF CONTENTS
<TABLE>
<S>                                                                        <C>
ARTICLE 1, DEFINITIONS ..................................................    2
    1.1   "AFFILIATE" ...................................................    2
    1.2   "AMGEN KNOW-HOW" ..............................................    2
    1.3   "AMGEN PATENT RIGHTS" .........................................    2
    1.4   "AMGEN TECHNOLOGY" ............................................    2
    1.5   "AMGEN TRADEMARKS" ............................................    2
    1.6   "CALENDAR QUARTER" ............................................    2
    1.7   "CALENDAR YEAR" ...............................................    3
    1.8   "CELL THERAPY PRODUCT(S)" .....................................    3
    1.9   "CHANGE OF CONTROL" ...........................................    3
    1.10  "CLINICAL TRIAL" ..............................................    3
    1.11  "CMC" .........................................................    3
    1.12  "COLLABORATION PRODUCT(S)" ....................................    3
    1.13  "COMMERCIAL EXPENDITURES" .....................................    3
    1.14  "COMMERCIAL PLAN" .............................................    3
    1.15  "COMMERCIALIZE" OR "COMMERCIALIZATION" ........................    3
    1.16  "COMMERCIALLY REASONABLE EFFORTS" .............................    3
    1.17  "CONFIDENTIAL INFORMATION" ....................................    4
    1.18  "CONTRIBUTED PRODUCT" .........................................    4
    1.19  "CONTROL" OR "CONTROLLED" .....................................    4
    1.20  "COVERED ENTITY" ..............................................    4
    1.21  "DERIVATIVE" ..................................................    5
    1.22  "DETAIL" OR "DETAILING" .......................................    5
    1.23  "DEVELOPMENT" OR "DEVELOP" ....................................    6
    1.24  "DEVELOPMENT PLAN" ............................................    6
    1.25  "DIRECT DEVELOPMENT COST" .....................................    6
    1.26  "DOLLAR" OR "$" ...............................................    6
    1.27  "DRUG APPROVAL APPLICATION" ...................................    6
    1.28  ""FDA" ........................................................    6
    1.29  "FIRST COMMERCIAL SALE" .......................................    6
    1.30  "FLT3-L" ......................................................    7
    1.31  "FORCE MAJEURE" ...............................................    7
    1.32  "GAAP" ........................................................    7
    1.33  "IND" .........................................................    7
    1.34  "INFORMATION" .................................................    7
    1.35  ""JOINT KNOW-HOW" .............................................    7
    1.36  "JOINT PATENT RIGHTS" .........................................    7
    1.37  "LOSSES" ......................................................    7
    1.38  "MAJOR MARKET COUNTRY" ........................................    7
    1.39  "MANUFACTURING PLAN" ..........................................    7
    1.40  "MANUFACTURING TRANSITION" ....................................    8
    1.41  "MATERIALS" ...................................................    8
    1.42  "NET SALES" ...................................................    8
    1.43  "OPERATING PROFIT OR LOSS" ....................................    8
</TABLE>






<PAGE>

<TABLE>
<S>                                                                        <C>
    1.44  "PATENT RIGHTS" ...............................................    8
    1.45  "PIVOTAL TRIAL(S)" ............................................    8
    1.46  "POST-APPROVAL CLINICAL STUDIES" ..............................    8
    1.47  "POST MARKETING APPROVAL STUDIES" .............................    9
    1.48  "PROCESS DEVELOPMENT/MANUFACTURING PLAN" ......................    9
    1.49  "PRODUCT LABELING" ............................................    9
    1.50  "PRODUCT TRADEMARK" ...........................................    9
    1.51  "PROGRAM PLAN" ................................................    9
    1.52  "PROMOTE" OR "PROMOTION" OR "PROMOTING" OR "PROMOTIONAL" ......    9
    1.53  "PROMOTIONAL MATERIALS" .......................................    9
    1.54  "RECALL" OR "RECALLING" .......................................   10
    1.55  "REGULATORY APPROVAL" .........................................   10
    1.56  "REGULATORY AUTHORITY" ........................................   10
    1.57  "REGULATORY FILINGS" ..........................................   10
    1.58  "REGULATORY PLAN": ............................................   10
    1.59  "REPRESENTATIVES" .............................................   10
    1.60  "SCF" .........................................................   10
    1.61  "TERRITORY" ...................................................   10
    1.62  "THIRD PARTY" .................................................   11
    1.63  "TRANSITION DATE" .............................................   11
    1.64  "UNOPTIONED CELL THERAPY PRODUCT(S)" ..........................   11
    1.65  "VIACELL KNOW-HOW" ............................................   11
    1.66  "VIACELL PATENT RIGHTS" .......................................   11
    1.67  "VIACELL TECHNOLOGY" ..........................................   11
    1.68  "VIACELL TRADEMARKS" ..........................................   11

ARTICLE 2, COLLABORATION ACTIVITIES AND GOVERNANCE ......................   11
    2.1   DEVELOPMENT PRIOR TO OPTION EXERCISE ..........................   11
    2.2   JOINT STEERING COMMITTEE ......................................   11
    2.3   JSC RESPONSIBILITIES ..........................................   11
    2.4   JSC MEETING PREPARATION .......................................   13
    2.5   DECISION MAKING; ADMINISTRATIVE MATTERS .......................   13
    2.6   SCIENTIFIC ADVISORY BOARD .....................................   15

ARTICLE 3, DEVELOPMENT ..................................................   15
    3.1   VIACELL RESPONSIBILITIES ......................................   15
    3.2   AMGEN RESPONSIBILITIES ........................................   15
    3.3   ADDITIONAL AMGEN ASSISTANCE ...................................   16
    3.4   DEVELOPMENT OBLIGATIONS .......................................   16
    3.5   INFORMATION AND DATA ..........................................   17
    3.6   AUDIT .........................................................   17

ARTICLE 4, AMGEN OPTION .................................................   17
    4.1   VIACELL REPORTING OBLIGATIONS .................................   17
    4.2   OPTION GRANT ..................................................   18
    4.3   OPTION EXERCISE ...............................................   18
</TABLE>


[**] Portions of this exhibit have been omitted pursuant to a confidential
treatment request. An unredacted version of this exhibit has been filed with the
Commission.


<PAGE>


<TABLE>
<S>                                                                        <C>
    4.4   PAYMENT OF DEVELOPMENT COSTS ..................................   18
    4.5   TRANSITION OF RESPONSIBILITIES ................................   18
    4.6   TRANSFERABILITY ...............................................   19
    4.7   OPT-OUT .......................................................   20

ARTICLE 5, REGULATORY ...................................................   20
    5.1   REGULATORY PLAN ...............................................   20
    5.2   REGULATORY LEAD ...............................................   20
    5.3   RESPONSIBILITIES AND RIGHTS OF REGULATORY LEAS ................   20
    5.4   RIGHT TO CROSS-REFERENCE IND AND EQUIVALENT FOREIGN FILINGS ...   21
    5.5   DRUG APPROVAL APPLICATIONS ....................................   21
    5.6   TRANSFER OF REGULATORY FILINGS AND REGULATORY APPROVALS .......   21
    5.7   ADVERSE EVENT REPORTING; CUSTOMER COMPLAINTS ..................   21
    5.8   COMMUNICATIONS ................................................   22
    5.9   APPLICATIONS FOR REGULATORY EXCLUSIVITY .......................   23
    5.10  RECALLS .......................................................   23
    5.11  MANUFACTURING .................................................   24
    5.12  COMPLIANCE WITH LAWS AND REGULATIONS ..........................   24

ARTICLE 6, COMMERCIALIZATION ............................................   24
    6.1   COMMERCIAL PLAN ...............................................   24
    6.2   RESPONSIBILITIES AND RIGHTS OF AMGEN ..........................   24
    6.3   MEDICAL AND OTHER INQUIRIES ...................................   25
    6.4   PROMOTIONAL MATERIALS .........................................   25

ARTICLE 7, MANUFACTURE AND SUPPLY .......................................   26
    7.1   MANUFACTURING PLAN ............................................   26
    7.2   RESPONSIBILITIES AND RIGHTS OF VIACELL ........................   27
    7.3   MANUFACTURE OF CONTRIBUTED PRODUCTS ...........................   30
    7.4   LIMITATION ON APPLICATION OF SUPPLY TERMS .....................   32

ARTICLE 8, COLLABORATION CONSIDERATION ..................................   32
    8.1   LICENSE FEE ...................................................   32
    8.2   MILESTONE PAYMENTS ............................................   32
    8.3   RELATED AGREEMENTS ............................................   32

ARTICLE 9, PROGRAM PLAN; OPERATING PROFIT OR LOSS .......................   32
    9.1   OPERATING PROFIT OR LOSS SHARING ..............................   32
    9.2   ACCOUNTING AND REPORTING OF COLLABORATION PROFITS AND LOSSES ..   32

ARTICLE 10, INTELLECTUAL PROPERTY .......................................   33
   10.1   TECHNOLOGY OWNERSHIP ..........................................   33
   10.2   CONTRIBUTED PRODUCT LICENSES; SUBLICENSE RIGHTS ...............   34
   10.3   COLLABORATION PRODUCT LICENSE; SUBLICENSE RIGHTS ..............   34
   10.4   PASS THROUGH RESTRICTIONS .....................................   35
   10.5   TRADEMARK LICENSE .............................................   35
</TABLE>

[**] Portions of this exhibit have been omitted pursuant to a confidential
treatment request. An unredacted version of this exhibit has been filed with the
Commission.


                                                                              3

<PAGE>

<TABLE>
<S>                                                                        <C>
   10.6   PROSECUTION ...................................................   36
   10.7   INFRINGEMENT OF PATENT RIGHTS AND PRODUCT TRADEMARKS ..........   38
   10.8   INFRINGEMENT OF THIRD PARTY RIGHTS ............................   39
   10.9   COOPERATION ...................................................   39
   10.10  TECHNICAL ASSISTANCE ..........................................   40
   10.11  EMPLOYEE OBLIGATIONS ..........................................   40
   10.12  PATENT MARKING ................................................   40
   10.13  THIRD PARTY RESEARCH AGREEMENTS ...............................   41
   10.14  NO IMPLIED LICENSES ...........................................   41

ARTICLE 11, PAYMENTS; RECORDS; AUDIT ....................................   41
   11.1   PAYMENTS ......................................................   41
   11.2   TAXES .........................................................   42
   11.3   RECORDS; AUDIT ................................................   42

ARTICLE 12, PUBLICATIONS ................................................   43
   12.1   PROCEDURE .....................................................   43
   12.2   CREDIT ........................................................   43

ARTICLE 13, CONFIDENTIALITY .............................................   44
   13.1   TREATMENT OF CONFIDENTIAL INFORMATION .........................   44
   13.2   AUTHORIZED DISCLOSURE .........................................   44
   13.3   TRANSFER OF MATERIALS .........................................   45
   13.4   PUBLICITY; TERMS OF AGREEMENT .................................   45

ARTICLE 14, REPRESENTATIONS, WARRANTIES AND COVENANTS ...................   46
   14.1   MUTUAL REPRESENTATIONS AND WARRANTIES .........................   46
   14.2   MUTUAL COVENANTS ..............................................   46
   14.3   ADDITIONAL REPRESENTATIONS, WARRANTIES AND COVENANTS OF VIACELL   47
   14.4   ADDITIONAL REPRESENTATIONS, WARRANTIES AND COVENANTS OF AMGEN .   48
   14.5   DISCLAIMERS ...................................................   48

ARTICLE 15, INDEMNIFICATION .............................................   48
   15.1   INDEMNIFICATION BY AMGEN ......................................   48
   15.2   INDEMNIFICATION BY VIACELL ....................................   49
   15.3   JOINT LIABILITY ...............................................   49
   15.4   INSURANCE .....................................................   50
   15.5   LIMITATION OF LIABILITY .......................................   50

ARTICLE 16, TERM AND TERMINATION ........................................   51
   16.1   TERM ..........................................................   51
   16.2   TERMINATION FOR DILIGENCE FAILURE .............................   51
   16.3   MUTUAL CONSENT ................................................   51
   16.4   TERMINATION FOR DEFAULT .......................................   51
   16.5   BANKRUPTCY ....................................................   52
   16.6   EFFECTS OF TERMINATION ........................................   52
</TABLE>



[**] Portions of this exhibit have been omitted pursuant to a confidential
treatment request. An unredacted version of this exhibit has been filed with the
Commission.

                                                                              4

<PAGE>

<TABLE>
<S>                                                                        <C>
   16.7   TRANSITION ....................................................   53
   16.8   ACCRUED RIGHTS ................................................   53

ARTICLE 17, DISPUTE RESOLUTION ..........................................   53
   17.1   DISPUTES ......................................................   53
   17.2   GOVERNING LAW; JUDICIAL RESOLUTION ............................   54

ARTICLE 18, GENERAL .....................................................   54
   18.1   FORCE MAJEURE .................................................   54
   18.2   NOTICES .......................................................   54
   18.3   MAINTENANCE OF RECORDS ........................................   55
   18.4   NO STRICT CONSTRUCTION ........................................   55
   18.5   PERFORMANCE BY AFFILIATES .....................................   55
   18.6   SUBCONTRACTING ................................................   56
   18.7   ASSIGNMENT ....................................................   56
   18.8   COUNTERPARTS ..................................................   56
   18.9   SEVERABILITY ..................................................   56
   18.10  HEADINGS ......................................................   57
   18.11  FURTHER ACTIONS ...............................................   57
   18.12  INDEPENDENT CONTRACTORS .......................................   57
   18.13  NO BENEFIT OF THIRD PARTIES ...................................   57
   18.14  USE OF NAMES, LOGOS OR SYMBOLS ................................   57
   18.15  NO WAIVER .....................................................   57
   18.16  OFFSET ........................................................   57
   18.17  EXPORT REQUIREMENTS ...........................................   58
   18.18  ENTIRE AGREEMENT; AMENDMENT ...................................   58
   18.19  EXHIBITS AND SCHEDULES ........................................   58

EXHIBIT A, AMGEN PATENT RIGHTS AS OF THE EFFECTIVE DATE..................  A-1
EXHIBIT B, ALLOWABLE COLLABORATION EXPENDITURES TO THE
           OPERATING PROFIT AND LOSS ACCOUNT.............................  B-1
EXHIBIT C, COVERED ENTITIES..............................................  C-1
EXHIBIT D, ADDITIONAL CONTRIBUTED PRODUCTS...............................  D-1
EXHIBIT E, FLT3 LIGAND AMINO ACID SEQUENCE...............................  E-1
EXHIBIT F, SCF AMINO ACID SEQUENCE.......................................  F-1
EXHIBIT G, VIACELL PATENT RIGHTS.........................................  G-1
EXHIBIT H, VIACELL TRADEMARKS............................................  H-1
</TABLE>

[**] Portions of this exhibit have been omitted pursuant to a confidential
treatment request. An unredacted version of this exhibit has been filed with the
Commission.

                                                                              5

<PAGE>



                             COLLABORATION AGREEMENT

      THIS COLLABORATION AGREEMENT (the "Agreement") is made effective as of
December 23, 2003 (the "Effective Date") by and between AMGEN INC., a Delaware
corporation having its principal place of business at One Amgen Center Drive,
Thousand Oaks, California 91320-1799 ("Amgen"), and VIACELL, INC., a Delaware
corporation having its principal place of business at 131 Clarendon Street,
Boston, Massachusetts 02116 ("ViaCell"). Amgen and ViaCell are sometimes
referred to herein individually as a "Party" and collectively as the "Parties".

                                    RECITALS

      WHEREAS, Amgen is a biopharmaceutical company with experience in the
research, development, manufacture, and commercialization of biotechnology and
pharmaceutical products for the treatment of human diseases;

      WHEREAS, ViaCell is a development stage cellular medicine company that has
expertise and technology relating to the use of stem cells in the production of
cell therapy products;

      WHEREAS, Amgen has developed certain technology and know-how that relates
to human proteins known as SCF and Flt3-L, which may be useful in the production
of ViaCell's cell therapy products;

      WHEREAS, ViaCell has technology, know-how, experience and expertise in the
research and development of ex vivo cell culture and cell therapy products that
may be improved or made possible by the use of SCF and Flt3-L;

      WHEREAS, ViaCell now wishes to obtain supplies of and a license under
Amgen's intellectual property rights in SCF and Flt3-L for use in ViaCell's
research and development activities relating to cell therapy products and
services;

      WHEREAS, the parties may wish to collaborate in the future with respect to
late stage clinical trials and commercialization of ViaCell's cell therapy
products on the terms and conditions set forth herein;

      WHEREAS, concurrently with the execution of this Agreement the Parties are
entering into a Securities Purchase Agreement whereby Amgen is making an equity
investment in ViaCell;

      NOW THEREFORE, based on the foregoing premises and the mutual covenants
and obligations set forth below, the Parties agree as follows:



[**] Portions of this exhibit have been omitted pursuant to a confidential
treatment request. An unredacted version of this exhibit has been filed with the
Commission.

                                                                              1

<PAGE>

                                   ARTICLE 1
                                   DEFINITIONS

      Capitalized terms used but not otherwise defined in this Agreement
(including in Exhibit B attached hereto) have the meanings set forth below:

      1.1 "AFFILIATE" shall mean, except as provided below, an individual, a
partnership, a joint venture, a corporation, a trust, an estate, an
unincorporated organization, a government or any department or agency thereof,
or any other entity or any combination of the aforementioned entities that,
directly or indirectly through one or more intermediaries, controls, is
controlled by or is under common control with a Party. For purposes of this
definition, "control" shall mean the possession, direct or indirect, of the
power to cause the direction of the management and policies of a Party, whether
through ownership of more than fifty percent (50%) of the voting securities of
such Party, by contract or otherwise.

      1.2 "AMGEN KNOW-HOW" shall mean all Information and Material Controlled by
Amgen on or following the Effective Date necessary to Develop, manufacture or
Commercialize Cell Therapy Products, Collaboration Products or Unoptioned Cell
Therapy Products, including but not limited to the following information: (1)
information disclosed in an IND for SCF and/or Flt3-L as of the Effective Date;
(2) information disclosed as of the Effective Date in any IND supplements for
SCF and/or Flt3-L; (3) all Amgen-sponsored collaborator data and results
(subject to any contractual confidentiality obligations of Amgen to Third
Parties regarding such results) that Amgen elects to and does provide to
ViaCell; (4) any regulatory data that Amgen elects to and does provide to
ViaCell; (5) sequence information or other technical information and trade
secrets relating to any Amgen Materials and information regarding their
structure, function and activity that Amgen elects to and does provide to
ViaCell; and (6) such other information that Amgen elects to and does disclose
to ViaCell, in each case that Amgen expressly designates in writing as
"confidential" or "proprietary" or that it otherwise designates as Amgen
Know-How under this Agreement; provided however, that Amgen Know-How shall
exclude Joint Know-How.

      1.3 "AMGEN PATENT RIGHTS" shall mean Amgen's rights in those Patent Rights
Controlled by Amgen on or following the Effective Date necessary to make or use
each Contributed Product including without limitation those patents and patent
applications listed in Exhibit A.

      1.4 "AMGEN TECHNOLOGY" shall mean all Amgen Patent Rights and Amgen
Know-How.

      1.5 "AMGEN TRADEMARKS" shall mean any and all corporate names, service
marks, logos or trademarks and trademark applications (whether or not
registered) together with all good will associated therewith, and any renewals,
extensions or modifications thereto either filed or used by Amgen.

      1.6 "CALENDAR QUARTER" shall mean the respective periods of three (3)
consecutive calendar months ending on either March 31, June 30, September 30, or
December 31 for so long as this Agreement is in effect.




[**] Portions of this exhibit have been omitted pursuant to a confidential
treatment request. An unredacted version of this exhibit has been filed with the
Commission.

                                                                              2

<PAGE>

      1.7 "CALENDAR YEAR" shall mean each successive period of twelve (12)
months commencing on January 1 and ending on December 31.

      1.8 "CELL THERAPY PRODUCT(S)" shall mean any treatment, whether a product
or a service, that utilizes cells or tissues that are manipulated and/or
expanded ex vivo, prior to use as a therapeutic agent to treat any injury,
disease or other condition, and which includes or is produced using a
Contributed Product, including without limitation, CB001, prior to the earlier
of the exercise of the Option or the expiration of the Option Period with
respect to such treatment. For the avoidance of doubt, once Amgen exercises its
Option with respect to a Cell Therapy Product, such Cell Therapy Product shall
be deemed a Collaboration Product and shall cease to be considered a Cell
Therapy Product. For the avoidance of doubt, once the Option Period expires
with respect to a Cell Therapy Product for an indication such Cell Therapy
Product for that indication shall be deemed an Unoptioned Cell Therapy Product
and shall cease to be considered a Cell Therapy Product.

[**] Portions of this exhibit have been omitted pursuant to a confidential
treatment request. An unredacted version of this exhibit has been filed with the
Commission.

                                                                              3

<PAGE>
      1.9 "CHANGE OF CONTROL" shall mean that ViaCell entered into a transaction
resulting in a transfer of [**] or more of the outstanding shares of ViaCell to
a Covered Entity.

      1.10 "CLINICAL TRIAL" shall mean any study to evaluate the safety and/or
the efficacy of a Cell Therapy Product or a Collaboration Product in humans,
including, without limitation a phase 1, phase 2, phase 3, phase 4 or other
clinical trial performed by or on behalf of either party.

      1.11 "CMC" shall mean the Chemistry Manufacturing Control section of a
Regulatory Filing.

      1.12 "COLLABORATION PRODUCT(S)" shall mean any Cell Therapy Product that
is developed or manufactured using a Contributed Product or any Derivative and
with respect to which Amgen exercised its Option.

      1.13 "COMMERCIAL EXPENDITURES" shall have the meaning set forth in Exhibit
B.

      1.14 "COMMERCIAL PLAN" shall mean the comprehensive plan and overall
strategy, and any updates thereto, for the Commercialization of Collaboration
Products (in accordance with customary standards for a product of comparable
market potential) including, without limitation, regulatory activities after the
Transition Date, Promotion, Detailing and other pre-launch and post-launch
marketing and sales activities. The Commercial Plan shall include, but not be
limited to, a reasonably detailed description of the schedule of work
activities, responsibility for the work activities and an associated budget.

      1.15 "COMMERCIALIZE" OR "COMMERCIALIZATION" shall mean all activities
(including the preparation and filing of Drug Approval Applications) relating to
the Promotion, Detailing, and other pre-launch and post-launch marketing and
sale activities of a Collaboration Product and shall include, without
limitation, Post-Approval Clinical Studies and regulatory affairs related to the
foregoing.

      1.16 "COMMERCIALLY REASONABLE EFFORTS" shall mean the level of efforts and
resources required to develop, manufacture or commercialize a Collaboration
Product in a sustained manner consistent with the efforts a similarly situated
biopharmaceutical company would typically devote to a product of similar market
potential, profit potential or strategic value resulting from its own research
efforts, based on conditions then prevailing. Commercially Reasonable Efforts
shall be determined on a country-by-country (each country including its
territories) basis for a particular Collaboration Product, and it is anticipated
that the level of effort will change over time reflecting changes in the status
of the Collaboration Product and the country (including its territories)
involved.

      1.17 "CONFIDENTIAL INFORMATION" shall mean, subject to the exceptions set
forth in the following sentence, any all Information received by either Party
("receiving Party") from the other Party ("disclosing Party") pursuant to this
Agreement that the disclosing Party has either marked as confidential or
proprietary, or has identified in writing as confidential or proprietary within
[**] after disclosure to the receiving Party in a non-written form.
"Confidential Information" shall not include any Information which:

[**] Portions of this exhibit have been omitted pursuant to a confidential
treatment request. An unredacted version of this exhibit has been filed with the
Commission.
<PAGE>
            (A) is publicly disclosed by the disclosing Party, either before or
after it becomes known to the receiving Party;

            (B) was known to the receiving Party, without obligation to keep it
confidential, prior to when it was received from the disclosing Party;

            (C) is subsequently disclosed to the receiving Party by a Third
Party lawfully in possession thereof without obligation to keep it confidential;

            (D) has been publicly disclosed other than by the disclosing Party
and without breach of an obligation of confidentiality with respect thereto; or

            (E) has been independently developed by the receiving Party without
the aid, application, reference to or use of Confidential Information, as
demonstrated by competent written proof.

      1.18 "CONTRIBUTED PRODUCT" shall mean (a) SCF, (b) Flt3-L and (c) any
cytokine or other Amgen Know-How or Material that Amgen Controls and which Amgen
has, in its sole discretion chosen to make available to ViaCell under this
Agreement, and which ViaCell has expressly accepted for use in connection with
Unoptioned Cell Therapy Products, Cell Therapy Products and/or Collaboration
Products under this Agreement, as listed on Exhibit D, as updated from time to
time by mutual agreement of the Parties.

      1.19 "CONTROL" OR "CONTROLLED" shall mean possession of the ability to
grant a license or sublicense as provided for herein under valid and subsisting
intellectual property rights without violating the terms of any agreement or
other arrangement with any Third Party or applicable law.

[**] Portions of this exhibit have been omitted pursuant to a confidential
treatment request. An unredacted version of this exhibit has been filed with the
Commission.                                                                    2
<PAGE>
      1.20 "COVERED ENTITY" shall mean a company that (i) Amgen can reasonably
demonstrate is or was involved, within the previous [**] including, without
limitation, those listed on Exhibit C, (ii) has a Market Capitalization of less
than $[**] or (iii) has a Market Capitalization of more than $[**] and [**]. For
purposes of this definition, "Market Capitalization" of a company shall mean (A)
if the company's common equity is publicly traded, the value of the outstanding
common equity based on (1) if the common equity is listed or admitted to trade
on a national securities exchange, the [**] closing price of the company's
common equity on the principal national securities exchange on which it is so
listed or admitted to trade [**], as published in the Wall Street Journal; (2)
if the common equity is not listed or admitted to trade on a national securities
exchange, the average of the closing price for the company's common equity [**],
as furnished by the National Association of Securities Dealers, Inc. ("NASD")
through the NASDAQ National Market Reporting System or a similar organization if
the NASD is no longer reporting such information; or (3) if the company's common
equity is not listed or admitted to trade on a national securities exchange and
is not reported on the National Market Reporting System, [**], as furnished by
the NASD or a similar organization; or (B) if the company's common equity is not
publicly traded and the NASD or a similar organization does not furnish the mean
between the bid and asked prices for the company's common equity, the fair
market value of the company's outstanding common equity [**].

      1.21 "DERIVATIVE" shall mean any modification of a Contributed Product,
wherein the modification is covered by one or more Patent Rights Controlled by
or licensed to Amgen.

      1.22 "DETAIL" OR "DETAILING" shall mean, with respect to a Collaboration
Product, an interactive face-to-face visit by a Party's sales representative
with a physician, designated by the Commercial Lead as a member of the target
call audience, at his or her office, at hospitals or at other locations
(excluding exhibits, displays and other forms of communication not involving
face-to-face contact by such sales representative), during which indicated uses,
safety, effectiveness, contraindications, side effects, warnings and/or other
relevant characteristics of a Collaboration Product as approved by a Regulatory
Authority are described in a fair and balanced manner consistent with the FD&C
Act (or equivalent laws in the Territory), as applicable, including, but not
limited to, the regulations at 21 CFR Part 202 and using, as necessary or
desirable, the Product Labeling (as defined herein) or the Promotional Materials
(as defined herein), in an effort to increase physician prescribing preferences
of such Collaboration Product for its approved indicated uses.

[**] Portions of this exhibit have been omitted pursuant to a confidential
treatment request. An unredacted version of this exhibit has been filed with the
Commission.
<PAGE>
      1.23 "DEVELOPMENT" OR "DEVELOP" shall mean all clinical development
activities undertaken to obtain Regulatory Approval for a Cell Therapy Product
or Collaboration Product in an indication in the Territory. For the avoidance of
doubt, these activities shall include clinical studies and clinical drug
development activities, including among other things: test method development
and stability testing, toxicology, formulation, process development, statistical
analysis and report writing, product approval and registration, and regulatory
affairs related to the foregoing. When used as a verb, "Develop" means to engage
in Development.

      1.24 "DEVELOPMENT PLAN" shall mean the comprehensive plan, overall
strategy and timelines, and any updates thereto, for the Development of Cell
Therapy Products and Collaboration Products (in accordance with customary
standards for a product of comparable market potential) including, without
limitation, the research, preclinical research, clinical studies, development/
manufacturing, clinical and regulatory activities required to obtain Regulatory
Approval(s) in the Territory. The Development Plan shall include, but not be
limited to, a reasonably detailed description of the schedule of work
activities, responsibility for the work activities and an associated budget.


      1.25 "DIRECT DEVELOPMENT COST" shall mean (i) actual Third Party charges
and fees paid by ViaCell for the performance of clinical development of Cell
Therapy Products, which become Collaboration Products upon Amgen exercising its
Option, (ii) ViaCell's labor cost directly related to clinical development of
Cell Therapy Products, which become Collaboration Products upon Amgen exercising
its Option, and (iii) ViaCell's labor cost and actual Third Party charges and
fees paid by ViaCell for the manufacture of Cell Therapy Products, which become
Collaboration Products upon Amgen exercising its Option [**]. All ViaCell labor
costs included under "Direct Development Cost" shall be charged at [**].


      1.26 "DOLLAR" OR "$" shall mean a United States dollar.

      1.27 "DRUG APPROVAL APPLICATION" shall mean an application for Regulatory
Approval required before commercial sale or use of a Collaboration Product as a
drug or to treat a particular indication in a regulatory jurisdiction, including
without limitation: (a) (i) a Biologics License Application (BLA) pursuant to 21
C.F.R. 601.2, submitted to the FDA or any successor application or procedure and
(ii) any counterpart of a U.S. BLA in another country in the Territory; and (b)
all supplements and amendments, including supplemental Biologics License
Applications (and any foreign counterparts) that may be filed (e.g., to expand
the label) with respect to the foregoing.

      1.28 "FDA" shall mean the United States Food and Drug Administration, or
any successor thereto.

[**] Portions of this exhibit have been omitted pursuant to a confidential
treatment request. An unredacted version of this exhibit has been filed with the
Commission.
<PAGE>
      1.29 "FIRST COMMERCIAL SALE" shall mean the initial transfer by a Party of
a Collaboration Product to a Third Party for any indication in exchange for cash
or some other consideration to which value can be assigned, following Regulatory
Approval to market such Collaboration Product.

      1.30 "FLT3-L" shall mean shall mean Amgen's Flt3 Ligand, a hematopoietic
growth factor, having the amino acid sequence which is set forth in Exhibit E.

      1.31 "FORCE MAJEURE" shall mean any occurrence beyond the reasonable
control of a Party that prevents or substantially interferes with the
performance by the Party of any of its obligations hereunder, if such occurs by
reason of any act of God, flood, fire, explosion, earthquake, breakdown of
plant, shortage of critical equipment, loss or unavailability of manufacturing
facilities or material, strike, lockout, labor dispute, casualty or accident, or
war, revolution, civil commotion, acts of public enemies, blockage or embargo,
or any injunction, law, order, proclamation, regulation, ordinance, demand or
requirement of any government or of any subdivision, authority or representative
of any such government, inability to procure or use materials, labor, equipment,
transportation or energy sufficient to meet manufacturing needs without the
necessity of allocation, or any other cause whatsoever, whether similar or
dissimilar to those above enumerated, beyond the reasonable control of such
Party, if and only if the Party affected shall have used reasonable efforts to
avoid such occurrence and to remedy it promptly if it shall have occurred.

      1.32 "GAAP" shall mean United States generally accepted accounting
principles.

      1.33 "IND" shall mean an Investigational New Drug application.

      1.34 "INFORMATION" shall mean all tangible and intangible techniques,
technology, practices, trade secrets, inventions (whether patentable or not),
methods, knowledge, know-how, conclusions, skill, experience, test data and
results (including pharmacological, toxicological and clinical test data and
results), analytical and quality control data, results or descriptions, software
and algorithms.

      1.35 "JOINT KNOW-HOW" shall mean Information and Materials characterized,
conceived, developed, derived, generated or identified jointly by employees of
or consultants to ViaCell and employees of or consultants to Amgen from the
Effective Date through the Term in the course of performing obligations or
exercising rights under this Agreement.

      1.36 "JOINT PATENT RIGHTS" shall mean all Patent Rights that claim or
disclose Joint Know-How.

      1.37 "LOSSES" shall mean liabilities, costs, fees, expenses and/or losses,
including without limitation reasonable legal costs, expenses and attorneys'
fees for outside counsel.

      1.38 "MAJOR MARKET COUNTRY" shall mean the United States, United Kingdom,
Italy, Germany, France or Japan.

[**] Portions of this exhibit have been omitted pursuant to a confidential
treatment request. An unredacted version of this exhibit has been filed with the
Commission.
<PAGE>
      1.39 "MANUFACTURING PLAN" shall mean the comprehensive plan, overall
strategy and timelines, and any updates thereto, for the manufacture of Cell
Therapy Products and Collaboration Products. The Manufacturing Plan shall
include, but not be limited to, a reasonably detailed description of the
schedule of work activities, responsibility for the work activities and an
associated budget.

      1.40 "MANUFACTURING TRANSITION" shall mean the process and change in the
rights and responsibilities of the Parties described in Section 7.2(g) of this
Agreement.

      1.41 "MATERIALS" shall mean biological materials including, but not
limited to, Contributed Products, screens, animal models, cell lines, cells,
nucleic acids, receptors, cytokines, proteins, reagents and other molecules.

      1.42 "NET SALES" shall mean all revenues recognized in accordance with
GAAP from the sale or other disposition of Collaboration Products by Amgen,
ViaCell or their respective Affiliates to a Third Party after deducting returns
and allowances (actually paid or allowed) including, [**]. Amounts received by a
Party or its Affiliates for the sale of Collaboration Products to such Party or
its Affiliates for resale shall not be included in the computation of Net Sales
hereunder.

      1.43 "OPERATING PROFIT OR LOSS" shall mean, for any period, the total Net
Sales of Collaboration Products less the sum of Allowed Expenditures.

<PAGE>
      1.44 "PATENT RIGHTS" shall mean (i) a pending application for a patent,
including without limitation any provisional, converted provisional, continued
prosecution application, continuation, divisional or continuation-in-part
thereof; or (ii) an issued, unexpired patent (with the term "patent" being
deemed to encompass, without limitation, an inventor's certificate) which has
not been held invalid or unenforceable by a court of competent jurisdiction from
which no appeal can be taken or has been taken within the required time period,
including without limitation any substitution, extension, registration,
confirmation, reissue, re-examination, renewal or any like filing thereof.

      1.45 "PIVOTAL TRIAL(S)" shall mean those clinical trials on sufficient
numbers of patients that, if the defined end-points are met, are designed (and
agreed to by the FDA, or other Regulatory Authorities in the Territory) based
upon existing data in the same patient population as of the start of the trial
to definitively establish that a drug is safe and efficacious for its intended
use, and to define warnings, precautions and adverse reactions that are
associated with the drug in the dosage range to be prescribed, and which provide
pivotal data supporting Regulatory Approval of such drug or label expansion of
such drug and that satisfy the requirements of 21 CFR 321.21(c), or its
successor regulation, or an equivalent foreign clinical trial.

      1.46 "POST-APPROVAL CLINICAL STUDIES" shall mean those clinical studies,
after Regulatory Approval of a Collaboration Product, approved by the JSC
including, but not limited to, Post Marketing Approval Studies, pharmacoeconomic
studies, pharmacoepidemiology studies, and investigator sponsored clinical
studies and, to the extent requested or modified from time to time, safety
surveillance studies.

      1.47 "POST MARKETING APPROVAL STUDIES" shall mean those clinical trials,
including safety surveillance studies, conducted under an IND which are agreed
upon by the Commercial Lead and a Regulatory Authority as a condition of
approval or maintenance of approval of a Drug Approval Application for a
Collaboration Product, as the case may be, other than patient registries of
other than a passive, non-interventional nature.

      1.48 "PROCESS DEVELOPMENT/MANUFACTURING PLAN" shall mean the comprehensive
plan and overall strategy, and any updates thereto, for process
development/manufacturing scale-up, manufacture, formulation, filling and/or
shipping of selected Collaboration Products (in accordance with customary
standards for a product of comparable market potential). The Process
Development/Manufacturing Plan shall include, but not be limited to, (i) a
reasonably detailed description of the schedule of work activities,
responsibility for the work activities and an associated budget of Collaboration
Products prior to completion of any Pivotal Trial therewith and (ii) a
reasonably detailed description of the schedule of work activities,
responsibility for the work activities and an associated budget of Collaboration
Products upon or after completion of any Pivotal Trial therewith.

      1.49 "PRODUCT LABELING" shall mean (a) the Regulatory Authority-approved
full prescribing information of a Collaboration Product, including any required
patient information

[**] Portions of this exhibit have been omitted pursuant to a confidential
treatment request. An unredacted version of this exhibit has been filed with the
Commission.
<PAGE>
and (b) all labels and other written, printed or graphic matter upon any
container, wrapper or any package insert or outsert utilized with or for a
Collaboration Product.

      1.50 "PRODUCT TRADEMARK" shall mean any trademarks and trade names (and
trademark applications (whether or not registered) together with all goodwill
associated therewith, and any renewals, extensions or modifications thereto in
the Territory), trade dress and packaging, in each case, which are applied to or
used with Collaboration Products or any Promotional Materials. "Product
Trademark" shall not include the marks AMGEN or VIACELL.

      1.51 "PROGRAM PLAN" shall mean the comprehensive plan and overall
strategy, and any updates thereto, for the Development and manufacture of Cell
Therapy Products and the Commercialization of Collaboration Products. The
Program Plan shall be comprised of the Development Plan, Manufacturing Plan,
Regulatory Plan, Commercial Plan and other allowable activities (and Other
Allowed Expenditures) and an associated budget for the foregoing.

      1.52 "PROMOTE" OR "PROMOTION" OR "PROMOTING" OR "PROMOTIONAL" shall mean,
with respect to a Collaboration Product, those activities and obligations other
than Detailing undertaken by a Party to encourage sales of such Collaboration
Product including, but not limited to, journal advertising, direct mail
programs, direct-to-consumer advertising, education, convention exhibits, and
other forms of advertising, promotion and any other communication specified in
any Commercial Plan.

      1.53 "PROMOTIONAL MATERIALS" shall mean all sales representative training
materials and all written, printed, graphic, electronic, audio or video matter
including, but not limited to, journal advertisements, sales visual aids, direct
mail, direct-to-consumer advertising, Internet postings, broadcast
advertisements, and sales reminder aids (e.g., scratch pads, pens and other such
items) intended for use or used by a Party in connection with any Promotion (as
defined herein) or Detailing of a Collaboration Product, except Product
Labeling.

      1.54 "RECALL" OR "RECALLING" shall mean an event, incident or circumstance
which may result in the need for a "recall" or "market withdrawal" (as such
terms are defined in U.S. regulations in 21 CFR 7.3 or other similar national,
state or local law or regulations) or field alert or field correction of a
Collaboration Product or any lots thereof.

      1.55 "REGULATORY APPROVAL" shall mean any approvals (including
supplements, amendments, pre- and post-approvals and price approvals), licenses,
registrations or authorizations (including designations of a Collaboration
Product as an "Orphan Product" under the Orphan Drug Act), howsoever called, of
any Regulatory Authority, which are necessary for the distribution, importation,
exportation, manufacture, production, use, storage, transport or clinical
testing and/or sale of a Cell Therapy Product or Collaboration Product in a
regulatory jurisdiction. Regulatory Approval shall not include any site license
for an Amgen manufacturing facility.

      1.56 "REGULATORY AUTHORITY" shall mean the FDA or any counterpart of the
FDA outside the United States, or other national, supra-national, regional,
state or local regulatory agency, department, bureau, commission, council or
other governmental entity with authority

[**] Portions of this exhibit have been omitted pursuant to a confidential
treatment request. An unredacted version of this exhibit has been filed with the
Commission.
<PAGE>
over the distribution, importation, exportation, manufacture, production, use,
storage, transport or clinical testing and/or sale of a Cell Therapy Product or
Collaboration Product.

      1.57 "REGULATORY FILINGS" shall mean, collectively, INDs, BLAs,
establishment license applications (ELAs) and drug master files (DMFs),
applications for designation of a Collaboration Product as an "Orphan
Product(s)" under the Orphan Drug Act or any other similar filings (including
any foreign equivalents and further including any related correspondence and
discussions), and all data contained therein, as may be required by the FDA or
equivalent foreign Regulatory Authorities for the Development, manufacture or
Commercialization of a Cell Therapy Product or Collaboration Product.

      1.58 "REGULATORY PLAN" shall mean the comprehensive plan or plans and
overall strategy, and any updates thereto, for preparing and filing any and all
Regulatory Filings regarding Cell Therapy Products or Collaboration Products (in
accordance with customary standards for a product of comparable market
potential) and for communications with Regulatory Authorities, including all
interactions with respect to such Regulatory Filings. The Regulatory Plan shall
include, but not be limited to, a reasonably detailed description of the
schedule of the work activities, responsibility for the work activities and an
associated budget.

      1.59 "REPRESENTATIVES" of a party shall mean all directors, officers,
employees, agents and advisors (including, without limitation, attorneys,
accountants, investment bankers and financial advisors) of such party and the
Affiliates of such party.

      1.60 "SCF" shall mean Amgen's Stem Cell Factor, an early-acting
hematopoietic growth factor, having the amino acid sequence which is set forth
in Exhibit F plus or minus a methionine at position -1.

      1.61 "TERRITORY" shall mean the world.

      1.62 "THIRD PARTY" shall mean any individual, partnership, joint venture,
corporation, trust, estate, unincorporated organization, government or any
department or agency thereof, or any other entity other than Amgen or ViaCell or
an Affiliate of either of them.

      1.63 "TRANSITION DATE" shall mean, with respect to a Collaboration
Product, the date that is [**] regarding such Collaboration Product.

[**] Portions of this exhibit have been omitted pursuant to a confidential
treatment request. An unredacted version of this exhibit has been filed with the
Commission.
<PAGE>
      1.64 "UNOPTIONED CELL THERAPY PRODUCT(S)" shall mean any Cell Therapy
Product for an indication for which the Option Period has expired.

      1.65 "VIACELL KNOW-HOW" shall mean all Information and Materials
Controlled by ViaCell on or following the Effective Date necessary to Develop,
manufacture or Commercialize Collaboration Products. "ViaCell Know-How" shall
not include Joint Know-How.

      1.66 "VIACELL PATENT RIGHTS" shall mean ViaCell's rights on or following
the Effective Date in all Patent Rights in force throughout the Territory having
at least one valid and enforceable claim covering the composition, manufacture
or use of Cell Therapy Products and/or Collaboration Products, including without
limitation those patents and patent applications listed in Exhibit G. "ViaCell
Patent Rights" shall not include Joint Patent Rights.

      1.67 "VIACELL TECHNOLOGY" shall mean all ViaCell Patent Rights and ViaCell
Know-How.

      1.68 "VIACELL TRADEMARKS" shall mean any and all corporate names, service
marks, logos or trademarks and trademark applications (whether or not
registered) together with all good will associated therewith, and any renewals,
extensions or modifications thereto either filed or used by ViaCell and listed
on Exhibit H, as updated from time to time by ViaCell.

                                    ARTICLE 2
                     COLLABORATION ACTIVITIES AND GOVERNANCE

      2.1 DEVELOPMENT PRIOR TO OPTION EXERCISE. ViaCell shall engage in research
and development activities with the goal of developing Cell Therapy Products.
Such research and development may, consistent with the terms of the licenses set
forth in this Agreement, include the use of the Contributed Products.

      2.2 JOINT STEERING COMMITTEE. As soon as practicable following the
Effective Date, the Parties shall establish a Joint Steering Committee (the
"JSC") comprised of [**] officers or managers from each of ViaCell and Amgen.

[**] Portions of this exhibit have been omitted pursuant to a confidential
treatment request. An unredacted version of this exhibit has been filed with the
Commission.
<PAGE>
      2.3 JSC RESPONSIBILITIES. The JSC shall be responsible for overseeing and
managing the collaboration with respect to Cell Therapy Products and
Collaboration Products, including, without limitation the following functions:

            (A) The JSC shall meet at least twice per Calendar Year. Such
meetings shall alternate between Amgen and ViaCell locations and be held at such
times as are agreed upon by the JSC. At least one JSC meeting per year shall be
conducted in person, whereas other JSC meetings may be held in person or by
video conference or teleconference. The first meeting shall be held at Amgen's
facilities within [**] of the Effective Date, and the agenda for such meeting
shall include a review of a program plan for 2004 including a budget for Direct
Development Costs for CB001 and any other Cell Therapy Products. If a Party's
representative is unable to attend a meeting, such Party may designate an
alternate representative to attend such meeting. In addition, each Party may, at
its discretion (and with the consent of the other Party, not to be unreasonably
withheld), invite additional employees, consultants or scientific advisors to
attend any JSC meetings.

            (B) The JSC shall review and discuss the progress of ViaCell's
Development and manufacturing of Cell Therapy Products and, if applicable,
Amgen's Development and Commercialization and ViaCell's manufacturing of
Collaboration Products, including review of plans, budgets, clinical trial
designs, data, results and other information in appropriate detail to enable the
JSC members to meaningfully monitor the progress of the Development,
manufacturing and Commercialization efforts of the Parties and to provide advice
and feedback relating thereto.

            (C) The JSC shall consider the applicability and usefulness of any
Materials that a Third Party or Amgen may (in its sole discretion) choose to
make available to ViaCell for use in producing or using the Cell Therapy
Products and/or the Collaboration Products.

            (D) Each year at the first JSC Meeting after the beginning of
ViaCell's fiscal year the JSC shall review an annual budget for projected Direct
Development Costs for each Cell Therapy Product for the following year prepared
by ViaCell in conjunction with ViaCell's annual budget process. At the first JSC
meeting after the end of ViaCell's fiscal year, the JSC shall review and
reconcile the actual Direct Development Costs for each Cell Therapy Product to
the budget previously reviewed. Upon approval by the JSC of the budget and the
reconciliation, such approvals shall be noted in the minutes of the JSC meeting.
[**].

            (E) For Collaboration Products, each Party shall submit to the JSC
for review prior to the end of [**] its [**] plans and budgets in draft form
covering activities for which it is responsible. [**].

            (F) The JSC shall perform such other functions as appropriate to
further the purposes of the collaboration pursuant to the terms and conditions
of this Agreement.

[**] Portions of this exhibit have been omitted pursuant to a confidential
treatment request. An unredacted version of this exhibit has been filed with the
Commission.
<PAGE>
      The JSC shall not have the authority to require Amgen or ViaCell to
undertake or modify any activities for which such Party is responsible under
this Agreement. Further, notwithstanding the above responsibilities of the JSC,
nothing in this Section 2.3 shall erode or detract from each Party's rights and
responsibilities for Developing, manufacturing and Commercializing Cell Therapy
Products and Collaboration Products pursuant to the Program Plan and as
described in this Agreement.

      2.4 JSC MEETING PREPARATION.

            (A) At least [**] prior to each regularly scheduled JSC meeting,
ViaCell shall provide to Amgen a report summarizing the progress of ViaCell's
research and Development efforts relating to Cell Therapy Products and its
manufacturing efforts related to Cell Therapy or Collaboration Products. After
each Transition Date and for so long as Amgen has primary responsibility for the
Development and Commercialization of a Collaboration Product(s), Amgen shall
provide to ViaCell a report summarizing the progress of Amgen's Development and
Commercialization efforts relating to Collaboration Products at least [**] prior
to each regularly scheduled JSC meeting.

            (B) ViaCell may provide to Amgen, and Amgen may consider, a request
for information relating to [**] Controlled by Amgen, which ViaCell believes may
have potential utility in Cell Therapy Products.

            (C) At least once per Calendar Year, Amgen shall provide to ViaCell
a summary report [**] and which Amgen believes may have potential utility in
Cell Therapy Products, and which Amgen (in its sole discretion) desires to make
available to ViaCell for use in the research and development of Cell Therapy
Products (if any). Amgen may elect to include in its summary report information
[**] that was the subject of a request for information under Section 2.4(b).

            (D) All reports, requests for information and other material
provided pursuant to Section 2.4 of this Agreement shall be provided in writing
to each member of the JSC.

      2.5 DECISION MAKING; ADMINISTRATIVE MATTERS.

            (A) Decision Making. All decisions of the JSC shall be made by the
[**] of ViaCell and Amgen, with the representatives of each Party who are
members of the JSC collectively having one vote in any matter requiring the
approval of the JSC.

            (B) Dispute Resolution. If the JSC is unable to reach [**] agreement
on any issue within a period of [**] after receiving written notification from a
Party of a dispute regarding such issue under this Agreement, then the final
decision-making authority for any such matter shall be determined, depending
upon the subject matter of the unresolved issue, as follows:

[**] Portions of this exhibit have been omitted pursuant to a confidential
treatment request. An unredacted version of this exhibit has been filed with the
Commission.
<PAGE>
            (I) Development decisions: Subject to the obligations set forth in
Section 5.7(a) to meet and cooperate with respect to Severe Adverse Events,
ViaCell shall have final decision-making authority with respect to Development
activities relating to all Cell Therapy Products, after reasonably considering
in good faith any concerns raised or comments promptly provided by Amgen.
Subject to the obligations set forth in Section 5.7(a) to meet and cooperate
with respect to Severe Adverse Events, Amgen shall have final decision-making
authority with respect to Development activities relating to all Collaboration
Products, after reasonably considering in good faith any concerns raised or
comments promptly provided by ViaCell.

            (II) Manufacturing decisions: Except for decisions relating to the
manufacture of Contributed Products, ViaCell shall have final decision-making
authority with respect to process development and manufacturing activities,
after reasonably considering in good faith any concerns raised or comments
promptly provided by Amgen. Subject to the provisions of Section 7.3 of this
Agreement, neither ViaCell nor the JSC shall have any authority relating to the
manufacture of Contributed Products, which shall be solely within the authority
and discretion of Amgen. The provisions of this Section 2.5(b)(ii) shall be
subject to Section 7.2(g), and upon and after a Manufacturing Transition, Amgen
shall have final decision-making authority with respect to process development
and manufacturing activities.

            (III) Regulatory decisions: ViaCell shall have final decision-making
authority with respect to all activities relating to obtaining Regulatory
Approvals for all Cell Therapy Products, after reasonably considering in good
faith any concerns raised or comments promptly provided by Amgen. Amgen shall
have final decision-making authority with respect to all activities relating to
obtaining Regulatory Approvals for all Collaboration Products, after reasonably
considering in good faith any concerns raised or comments promptly provided by
ViaCell.

            (IV) Commercialization decisions: Amgen shall have final
decision-making authority with respect to Commercialization activities relating
to all Collaboration Products, after reasonably considering in good faith any
concerns raised or comments promptly provided by ViaCell. For the avoidance of
doubt, neither Party shall have any rights to commercialize Cell Therapy
Products and ViaCell reserves for itself all rights to commercialize all
Unoptioned Cell Therapy Products.

            (V) All other Decisions: The Parties shall attempt to resolve
disputes arising under, or relating to, this Agreement that concern matters not
listed in (i) - (iv) above in accordance with the provisions of Article 17,
below.

For the avoidance of doubt, control of final decision-making authority for any
matter as set forth in Sections 2.5(b)(i)-(iv) shall not relieve the Party with
such final decision-making authority from any of its representations, warranties
and/or covenants as set forth in Article 14 nor shall it enable such Party to
unilaterally modify or amend the terms of this Agreement.
<PAGE>
            (C) Administrative Matters. The JSC shall establish its own
procedural rules for its operation, consistent with the terms of this Section
2.5. A chairperson for the JSC shall be appointed from among its members. The
chairperson shall be appointed on an annual basis and will be a ViaCell
representative prior to the Transition Date of the first Collaboration Product
and an Amgen representative after the Transition Date of the first Collaboration
Product. The chairperson shall be responsible for calling meetings of the JSC
and for leading the meetings. A JSC member of the Party hosting a meeting of the
JSC shall serve as secretary of that meeting. Within [**] following each
meeting, the secretary of such meeting shall prepare and distribute to all
members of the JSC the minutes of the meeting. Such minutes shall provide a
reasonably detailed description of the meeting discussions and a list of any
actions, decisions or determinations approved by the JSC. The minutes of each
JSC meeting shall be approved or disapproved, and revised as necessary, at the
next meeting. Final minutes of each meeting shall be distributed to the members
of the JSC by the chairperson.

      2.6 SCIENTIFIC ADVISORY BOARD.

            (A) During the Term, ViaCell shall arrange for at least one senior
Amgen scientist identified by Amgen, who shall initially be Dr. Glenn Begley,
Senior Director, Basic Research, Hematology (the "MSAB Nominee"), to serve as a
member of ViaCell's Medical Scientific Advisory Board. Amgen, in its sole
discretion, shall have the right to replace such MSAB Nominee at any time upon
written notice to ViaCell.

            (B) ViaCell shall retain the right at all times to exclude the MSAB
Nominee from segments of its Medical Scientific Advisory Board meetings that do
not relate to Cell Therapy Products or Collaboration Products. Amgen and the
MSAB Nominee shall retain the right at all times to recuse the MSAB Nominee from
any meeting or segments of a meeting of ViaCell's Scientific Advisory Board.

            (C) The Parties understand and acknowledge that the MSAB Nominee is
intended solely to provide ViaCell with strategic technical scientific input,
and is not intended to confer on Amgen, the MSAB Nominee or any employees,
officers or directors of Amgen any duties to ViaCell, including, without
limitation, fiduciary duties or rights. ViaCell further understands that Amgen's
employees, officers and directors owe duties solely to Amgen, its subsidiaries
and Affiliates. Any advice provided by Amgen, its employees, officers and
directors is provided with no warranties of any kind, and ViaCell shall
indemnify, defend and hold Amgen harmless for any claims that may result from
its reliance thereon.

                                    ARTICLE 3
                                   DEVELOPMENT

      3.1 VIACELL RESPONSIBILITIES.

            (A) ViaCell shall be responsible for preparing and submitting the
Development Plan section of the Program Plan with respect to Cell Therapy
Products to and for approval by the JSC, and shall update the Development Plan
on an annual basis, in time for the annual budget cycle of each of the Parties;
provided however, it is acknowledged and agreed that

[**] Portions of this exhibit have been omitted pursuant to a confidential
treatment request. An unredacted version of this exhibit has been filed with the
Commission.
<PAGE>
the Development Plan may need to be modified from time to time between annual
updates, based upon the results of clinical trials and other unanticipated
events. [**].

[**] Portions of this exhibit have been omitted pursuant to a confidential
treatment request. An unredacted version of this exhibit has been filed with the
Commission.
<PAGE>
            (B) ViaCell shall have responsibility for all aspects of Developing
the Cell Therapy Products in the Territory, including making all strategic and
tactical decisions with respect thereto in accordance with the Development Plan
and establishing the methods and means by which it performs its obligations
under this Agreement (including the management of permitted subcontractors,
pursuant to Section 18.6).

            (C) ViaCell hereby covenants that it shall use Commercially
Reasonable Efforts to generate data as soon as practicable from a Phase 1
clinical trial, and, if applicable, from a Phase 2 clinical trial, all in
accordance with the Development Plan approved by the JSC.

      3.2 AMGEN RESPONSIBILITIES.

            (A) Amgen shall be responsible for preparing and submitting the
Development Plan section of the Program Plan with respect to the Collaboration
Products to and for approval by the JSC, and shall update the Development Plan
on an [**] basis, [**]; provided however, it is acknowledged and agreed that the
Development Plan may need to be modified from time-to-time[**], based upon the
results of clinical trials and other unanticipated events. [**].

            (B) Amgen shall have responsibility for all aspects of Developing
the Collaboration Products in the Territory, including making all strategic and
tactical decisions with respect thereto in accordance with the Development Plan
and establishing the methods and means by which it performs its obligations
under this Agreement (including the management of permitted subcontractors,
pursuant to Section 18.6). For the avoidance of doubt, Amgen shall use its
Commercially Reasonable Efforts in relation to creating and amending the
Development Plan in a manner that is reasonable and in exercising
decision-making with respect to the Development of the Collaboration Products.

      3.3 ADDITIONAL AMGEN ASSISTANCE. Upon the request of ViaCell, Amgen [**]
to assume certain Development responsibilities in support of ViaCell's carrying
out the activities within the Development Plan. Prior to assuming any such
responsibility, Amgen shall provide to ViaCell, for approval by the JSC and
inclusion within the Development Plan, the estimated budget for carrying out any
such responsibility. Immediately upon execution of such responsibilities, Amgen
may charge its expenses associated therewith to ViaCell in the form of written
invoices to be paid within [**] of receipt.

[**] Portions of this exhibit have been omitted pursuant to a confidential
treatment request. An unredacted version of this exhibit has been filed with the
Commission.
<PAGE>
      3.4 DEVELOPMENT OBLIGATIONS. Each Party shall be responsible for carrying
out its activities in accordance with the Development Plan. These activities
shall include, without limitation (i) identifying and carrying out all major
Development tasks to be conducted prior to submission of filings for Regulatory
Approval of a Collaboration Product for a particular indication; (ii)
identifying key Development objectives, expected associated resources, risk
factors, timelines, go/no go decision points and relevant decision criteria;
(iii) carrying out all aspects of (e.g., designing studies and protocols and
conducting), and preparing the associated Regulatory Plan for, all clinical
trials necessary to obtain Regulatory Approval for each indication pursued, as
well as establishing new dosage forms, new formulations or other enhancements of
approved Collaboration Products (but excluding Post-Approval Clinical Studies)
including, but not limited to (1) establishing/contracting with clinical sites,
investigators and contract research organizations ("CROs"), (2) enrolling
clinical study patients, (3) organizing investigator meetings, scientific
meetings, advisory panel workshops and regulatory meetings, and (4) analyzing,
summarizing and presenting clinical study results; (iv) performing any other
additional research and pre-clinical research in support of the clinical
development of Collaboration Products; (v) forecasting clinical manufacturing
production requirements; and (vi) Regulatory Authority reporting on study
design, study outcome, other communications and regulatory filings (to the
extent not covered by a Regulatory Plan).

      3.5 INFORMATION AND DATA.

            (A) ViaCell shall promptly disclose to Amgen all material scientific
or technical information relating to any Collaboration Product that it discovers
in the course of Development activities, promptly after it is learned or its
materiality is appreciated. ViaCell shall maintain a database which contains (i)
all clinical trial data accumulated from clinical trials of all Cell Therapy
Products, (ii) all safety data, and (iii) all adverse reaction information for
all Cell Therapy Products. On an annual basis, ViaCell shall provide Amgen with
written summaries of all pre-clinical and clinical data generated by or on
behalf of ViaCell with respect to Cell Therapy Products, as well as all such
pre-clinical and clinical data in an industry standard computer readable format
requested by Amgen. Amgen shall be entitled to have access, during regular
business hours and upon reasonable advance notice, to such pre-clinical and
clinical data maintained by ViaCell (including all clinical trial databases, in
an industry standard computer readable format requested by Amgen). ViaCell shall
ensure that its preclinical and clinical trials are monitored and audited in
accordance with industry standards.

            (B) Amgen shall promptly disclose to ViaCell all material scientific
or technical information relating to any Cell Therapy Product or Collaboration
Product that it discovers in the course of Development activities, promptly
after it is learned or its materiality is appreciated. Amgen shall maintain a
database which contains (i) all clinical trial data accumulated from clinical
trials of all Collaboration Products, (ii) all safety data, and (iii) all
adverse reaction information for all Collaboration Products. On an annual basis,
Amgen shall provide ViaCell with written summaries of all clinical data
generated by Amgen with respect to Collaboration Products, as well as such
clinical data in an industry standard computer readable format requested by
ViaCell. ViaCell shall be entitled to have access, during regular business hours
and upon reasonable advance notice to such clinical data maintained by Amgen
(including all clinical trial databases, in an industry standard computer
readable format requested by
<PAGE>
ViaCell). Amgen shall ensure that its preclinical and clinical trials are
monitored and audited in accordance with industry standards.

      3.6 AUDIT. Amgen shall have the right to conduct reasonable quality
assurance audits with respect to all facilities, clinical sites, operations and
laboratories (and any records related thereto) of ViaCell or Third Party
subcontractors, where Development activities are conducted, as is reasonably
necessary solely for the purpose of verifying ViaCell's conformance with
applicable cGMP, cGLP, cGCP and other regulatory requirements. Such audits shall
be conducted upon reasonable notice during reasonable business hours.

                                    ARTICLE 4
                                  AMGEN OPTION

      4.1 VIACELL REPORTING OBLIGATIONS. Upon completing the data collection and
analysis resulting from each Clinical Trial for any Cell Therapy Product,
ViaCell shall promptly provide to the JSC a detailed written report describing
the Clinical Trial results and sufficient related information necessary to
evaluate future development options and requirements. The JSC shall promptly
review such report to determine whether the form and substance of the report
meet standards for such reports in the pharmaceutical and biotechnology
industries, and, if applicable, suggest changes or improvements thereto.
Promptly after approval of such report by the JSC, ViaCell shall provide a copy
of the approved report to Amgen. Such report shall include a detailed written
account of the Direct Development Costs approved pursuant to Section 2.3,
incurred up to that date, itemized by product and by indication.

      4.2 OPTION GRANT. ViaCell hereby grants to Amgen, and Amgen hereby accepts
a worldwide, exclusive option to select as a Collaboration Product any Cell
Therapy Products that are researched, developed or made using any Contributed
Product (the "Option"). For the avoidance of doubt, upon the exercise of the
Option, Amgen will automatically receive (and ViaCell hereby grants to Amgen) a
worldwide, exclusive license under the ViaCell Technology sufficient to make,
have, made, use, sell, promote, import and export the Collaboration Products,
provided, however, that the rights to make and have made shall be retained by
ViaCell until and unless Amgen exercises its right to assume the rights and
responsibilities of Manufacturing Lead under Section 7.1(f).



<PAGE>

      4.3   OPTION EXERCISE. Prior [**] for each Cell Therapy Product [**],
ViaCell shall provide to Amgen a notice of ViaCell's intent to commence such
[**] (which notice shall be provided only after ViaCell has provided to Amgen a
detailed written report in relation to [**], the results of which support the
commencement of the [**], which report has been approved by the JSC in
accordance with Section 4.1 of this Agreement), and Amgen shall have the right
to exercise the Option within [**] of receiving such notice from ViaCell or at
any time prior to receiving such notice from ViaCell (the "Option Period").
Should Amgen choose to exercise an Option, it must do so by providing to ViaCell
a written notice thereof (an "Exercise Notice"). For the avoidance of doubt,
Amgen shall have the right to exercise each Option on a product-by-product and
indication-by-indication basis. If Amgen does not exercise the Option prior to
the expiration of the Option Period with respect to a Cell Therapy Product for
an indication, then that Cell Therapy Product for that indication will be deemed
an Unoptioned Cell Therapy Product and Amgen will no longer have an Option with
respect to that Cell Therapy Product for that indication.

      4.4   PAYMENT OF DEVELOPMENT COSTS. Within [**] of the Transition Date,
Amgen shall pay to ViaCell [**] of the Direct Development Costs incurred prior
to the Transition Date for the Collaboration Product and indication for which
Amgen has exercised its Option.

      4.5   TRANSITION OF RESPONSIBILITIES. After Amgen's exercise of the Option
and prior to the Transition Date, ViaCell will transfer to Amgen the IND and all
other Regulatory Filings for the Collaboration Product for which Amgen exercised
its Option. ViaCell shall also deliver to Amgen a complete copy of the IND and
any other Regulatory Filings for the Collaboration Product for which Amgen has
exercised its Option and any related correspondence with the FDA and any other
Regulatory Authority relating thereto, as well as all related Information and
Materials (including but not limited to data and results of Phase 1, Phase 2
and/or Phase 3 clinical trials, to the extent applicable). On and after the
Transition Date for a Collaboration Product, ViaCell will provide all assistance
and execute all documents reasonably requested to facilitate the transition of
the Development responsibilities, as described in Article III, and the
responsibilities of the Commercial Lead, as described in Article VI, for that
Collaboration Product to Amgen. For the avoidance of doubt, the exercise of the
Option will not affect the rights and responsibilities of the Parties with
respect to Cell Therapy Products and/or indications for which the Option Period
has not expired. [**].

      4.6   TRANSFERABILITY. Except as otherwise set forth below or as otherwise
explicitly permitted by this Agreement, neither Party shall have the right to
assign, sublicense or transfer its rights with respect to any Cell Therapy
Product or Collaboration Product.



[**] Portions of this exhibit have been omitted pursuant to a confidential
treatment request. An unredacted version of this exhibit has been filed with the
Commission.
<PAGE>
            (A)   Either Party shall have the right to assign its rights to any
or all Collaboration Products, provided however, that prior to such assignment,
that Party (the "Transferring Party") first provides the other Party (the
"Non-Transferring Party") [**] The Non-Transferring Party's [**] first shall
commence upon the Transferring Party providing a written notice describing in
detail the rights (including rights to any tangible or intangible property) it
desires to assign to a Third Party [**] Upon receipt of a [**] the
Non-Transferring Party shall have a [**] in which to determine whether it
desires to [**] proposing the terms on which [**] (if at all). In the event that
the Transferring Party desires to [**] the parties shall [**] of the definitive
documents required to [**] In the event that (i) the Transferring Party does not
desire to [**] such Assets to the Non-Transferring Party [**] or (ii) the
Parties are unable to [**] of the date on which the Transferring Party indicates
its desire to [**] such Assets to the Non-Transferring Party [**] then the
Transferring Party shall [**] In the event that the Non-Transferring Party does
not [**] then the Transferring Party shall [**] In the event that ViaCell
assigns its rights to any Collaboration Product to any Third Party under this
Section 4.6(a), Amgen shall have the right [**] with respect to such
Collaboration Product, which right is exercisable within [**]

            (B)   For the avoidance of doubt, ViaCell shall have the right to
assign its rights to any Unoptioned Cell Therapy Product without restriction.

            (C)   In the event of a Change of Control of ViaCell, [**] for any
and/or all Collaboration Products which right is exercisable within [**] after
the date Amgen became aware that the Change of Control occurred. At any time
after a Change of Control of ViaCell, for each Cell Therapy Product for which
Amgen elects to exercise its Option, [**], which right is exercisable within
[**] of the date of the exercise of the Option with respect to such Cell Therapy
Product.

      4.7   OPT-OUT. Each party shall have the right, upon [**] written notice
(an "Opt-Out Notice") to the other Party to opt out of its rights with respect
to any Collaboration Product. [**] after delivering such Opt-Out Notice (the
"Opt-Out Date") to the other Party, the Party so doing shall completely forfeit
all rights under this Agreement with respect to the Collaboration Product(s)
listed in the Opt-Out Notice, and all remaining rights shall immediately vest in
the other Party. The Party opting out shall, however, be responsible for and
obligated with respect to (i) [**] and (ii) providing all assistance and
executing all documents as the other Party may reasonably request to facilitate
or assist in transitioning the roles and responsibilities previously held by the
Party opting out, subject to the terms of Section 7.3 below.



[**] Portions of this exhibit have been omitted pursuant to a confidential
treatment request. An unredacted version of this exhibit has been filed with the
Commission.
<PAGE>
                                    ARTICLE 5
                                   REGULATORY

      5.1   REGULATORY PLAN(A) ViaCell shall be responsible for preparing and
submitting the Regulatory Plan section of the Program Plan with respect to Cell
Therapy Products to and for approval by the JSC, and shall update the Regulatory
Plan on an [**] basis, [**]; provided however, it is acknowledged and agreed
that the Regulatory Plan may need to be modified from time to time between [**]
updates, based upon the results of clinical trials and other unanticipated
events. [**].

            (B)   Amgen shall be responsible for preparing and submitting the
Regulatory Plan section of the Program Plan with respect to Collaboration
Products to and for approval by the JSC, and shall update the Regulatory Plan on
an [**] basis, [**]; provided however, it is acknowledged and agreed that the
Regulatory Plan may need to be modified from time to time between [**] updates,
based upon the results of clinical trials and other unanticipated events. [**].

      5.2   REGULATORY LEAD. ViaCell shall be responsible for all regulatory
matters for Cell Therapy Products and Amgen shall be responsible for all
regulatory matters for Collaboration Products and each shall be referred to as
the "Regulatory Lead" therefor. Regulatory matters shall include, without
limitation, the filing and support of any Drug Approval Applications and matters
concerning Post-Approval Clinical Studies.

      5.3   RESPONSIBILITIES AND RIGHTS OF REGULATORY LEAD. During the time
period for which it is responsible for regulatory matters, the Regulatory Lead
for a product and/or indication shall be the trial sponsor with Regulatory
Authorities. With respect to regulatory matters for which it is responsible, the
Regulatory Lead for a product and/or indication shall have the right to monitor,
review and direct all aspects of regulatory matters relating thereto, including
making all strategic and tactical decisions with respect thereto (in accordance
with the Regulatory Plan) and establishing the methods and means by which it
performs such services, including the management of permitted subcontractors,
pursuant to Section 18.6. The Regulatory Lead shall have responsibility for all
associated official correspondence, communications and Regulatory Filings with
Regulatory Authorities regarding such matters.



[**] Portions of this exhibit have been omitted pursuant to a confidential
treatment request. An unredacted version of this exhibit has been filed with the
Commission.
<PAGE>
      5.4   RIGHT TO CROSS-REFERENCE IND AND EQUIVALENT FOREIGN FILINGS. ViaCell
shall have the right to cross-reference Amgen's IND and equivalent foreign
filings for Contributed Products solely for the purpose of Development and
Commercialization of Cell Therapy Products, Collaboration Products and
Unoptioned Cell Therapy Products. For the avoidance of doubt, ViaCell shall not
have the right, for any reason or under any circumstance, to access, copy or
review Amgen's INDs or equivalent foreign filings for Contributed Products. In
the event that a Regulatory Authority requests information from ViaCell related
to the manufacture or quality of Contributed Products and ViaCell is required to
supply such information to the Regulatory Authority in order to pursue or
maintain Regulatory Approval for a Cell Therapy Product, Collaboration Product
or Unoptioned Cell Therapy, at ViaCell's request [**], Amgen shall provide the
requested information by either of the following methods, as elected by Amgen
[**]: (i) directly to the Regulatory Authority requesting such information; or
(ii) to ViaCell, in order for ViaCell to respond to the Regulatory Authority's
request in a timely manner.

      5.5   DRUG APPROVAL APPLICATIONS. Amgen shall own (be the sponsor and
party of record of) all Drug Approval Applications for Collaboration Products in
the Territory, and ViaCell shall own (be the sponsor and party of record of) all
Drug Approval Applications for Cell Therapy Products in the Territory.

      5.6   TRANSFER OF REGULATORY FILINGS AND REGULATORY APPROVALS. If
ownership of a Regulatory Filing or Regulatory Approval in any country cannot be
transferred from the owning Party to the other Party pursuant to the terms of
this Agreement, the owning Party shall grant to the other Party an exclusive
right of access and reference to such Regulatory Filing or Regulatory Approval
in such country in order to enable the other Party to become a sponsor and party
of record of an IND or equivalent foreign filing. If such right of access and
reference is not sufficient to permit the other Party to file a Drug Approval
Application and receive Regulatory Approval or to Develop, manufacture or
Commercialize a Collaboration Product, the owning Party shall provide the other
Party with any and all information necessary for the other Party to carry out
such activities and to receive Regulatory Approval in its own name.

      5.7   ADVERSE EVENT REPORTING; CUSTOMER COMPLAINTS.

            (A)   ViaCell shall maintain a record of all non-medical and medical
product-related complaints and reports of adverse events that it receives with
respect to each Cell Therapy Product, and Amgen shall maintain a record of all
non-medical and medical product-related complaints and reports of adverse events
that it receives with respect to each Collaboration Product. At least [**] per
[**], each Party shall provide to the other with copies of any complaint
(including all adverse events) received by it relating to a Cell Therapy Product
and/or a Collaboration Product. In the event of the occurrence of any serious
adverse event(s) (as defined in ICH Guideline E2A), the Parties shall meet (in
person or via telephone) within [**] of first becoming aware of such occurrence
to discuss steps necessary to address any safety concerns and share any relevant
information regarding such occurrence



[**] Portions of this exhibit have been omitted pursuant to a confidential
treatment request. An unredacted version of this exhibit has been filed with the
Commission.
<PAGE>
            (B)   On an indication-by-indication basis for each Cell Therapy
Product, ViaCell (as the IND sponsor and party of record) shall be responsible
for reporting to Regulatory Authorities any adverse experience and safety issues
for such Cell Therapy Product in compliance with the requirements of all
applicable laws and regulations (including the FD&C Act and the PHS Act, and any
amendments thereto and the regulations promulgated thereunder, and the
equivalent laws, rules and regulations of other countries in the Territory) and
shall promptly thereafter provide Amgen with a copy of such report.

            (C)   On an indication-by-indication basis for each Collaboration
Product, Amgen shall be responsible (as the IND sponsor and party of record) for
reporting to Regulatory Authorities any adverse experience and safety issues
regarding such Collaboration Product in compliance with the requirements of all
applicable laws and regulations (including the FD&C Act and the PHS Act, and any
amendments thereto and the regulations promulgated thereunder, and the
equivalent laws, rules and regulations of other countries in the Territory) and
shall promptly thereafter provide ViaCell with a copy of such report.

      5.8   COMMUNICATIONS.

            (A)   The Regulatory Lead for a product and/or indication under this
Agreement shall have exclusive responsibility for all correspondence and for any
official communication (except as the other Party may be required by applicable
laws or regulations or a Regulatory Authority to communicate) regarding such
product and/or indication with applicable Regulatory Authorities in the
Territory and the other Party shall have the right to be present (and to
participate at the request of the Regulatory Lead or the Regulatory Authority)
at all face-to-face meetings and scheduled conference calls regarding
significant clinical events or decisions. If one Party is required by applicable
laws or regulations or a Regulatory Authority to disclose information to such
Regulatory Authority having jurisdiction in the Territory, including information
regarding the manufacture of Cell Therapy Products and/or Collaboration
Products, such Party will notify the other Party before communicating with the
Regulatory Authority.

            (B)   ViaCell (to the extent it is the Manufacturing Lead) will
reasonably cooperate with Amgen to make and provide copies of any direct
communications by ViaCell with the Regulatory Authorities having jurisdiction in
the Territory regarding the manufacture of any Collaboration Product by ViaCell
for supply to Amgen; provided, however, that ViaCell's obligation to provide
Amgen with information relating to the manufacture of the Collaboration
Product(s) is limited to the circumstance where such information is reasonably
required for Amgen to carry out its responsibilities Developing the
Collaboration Product and/or as Regulatory Lead and/or Commercial Lead, or is
required by law, rule, regulation or a Regulatory Authority having jurisdiction
in the Territory, to have access; but Amgen shall only be entitled to use such
information to the extent required by such law, rule, regulation or Regulatory
Authority or to the extent reasonably required to carry out its responsibilities
under this Agreement, including its Development responsibilities and/or its
responsibilities as Regulatory and/or Commercial Lead. For so long as ViaCell is
supplying Amgen with Collaboration Products hereunder, ViaCell shall have the
right to be present at all meetings and to participate in all
<PAGE>
telephone calls with Regulatory Authorities having jurisdiction in the Territory
wherein the CMC contained in any Regulatory Filing is to be discussed.

            (C)   Each Party shall promptly notify the other Party of and
provide such other Party with a copy of any correspondence or other reports or
complaints submitted to or received from any Regulatory Authority, or other
Third Party claiming that any Promotional Materials are inconsistent with the
Product Labeling or are otherwise in violation of any applicable laws and
regulations (including the FD&C Act and the PHS Act, and any amendments thereto
and the regulations promulgated thereunder, and the equivalent laws, rules and
regulations of other countries in the Territory).

      5.9   APPLICATIONS FOR REGULATORY EXCLUSIVITY. The Parties recognize that
exclusivity rights granted or provided for under regulatory laws of the
countries of the Territory may be commercially significant to Collaboration
Products. To the extent permitted by law, as between the Parties, Amgen shall
have the exclusive right to file for, request and maintain any regulatory
exclusivity rights for Collaboration Products in the Territory (including
without limitation regulatory exclusivity rights based upon an orphan drug
designation of a Collaboration Product) and to conduct and prosecute any
proceedings or actions to enforce such regulatory exclusivity rights.

      5.10  RECALLS.

            (A)   The Parties shall exchange their internal standard operating
procedures, if any, as to product recalls ("SOPs") reasonably promptly after the
Effective Date and thereafter reasonably promptly after such SOPs are approved
or modified. If either Party becomes aware of information about quantities of
Collaboration Product supplied from ViaCell to Amgen, which may not conform to
the specifications for such Collaboration Product, or for which there are
potential adulteration, misbranding and/or other issues regarding safety or
effectiveness, or for which the Collaboration Product itself is alleged or
proven to be the subject of a Recall in any country in the Territory, it shall
promptly so notify the other Party and the Party having the right to control
such a Recall pursuant to Section 5.10(b) may take [**] when the regulatory
timeframes or public safety considerations so require. In all other
circumstances, Recalls can only be made by [**] consent of the JSC and shall be
made by the Party having the first right to control a Recall pursuant to Section
5.10(b). The JSC will meet (in person, by telephone or otherwise) to discuss
such other circumstances and to consider appropriate courses of action, which
courses of action with respect to a Recall shall be consistent with the internal
SOP of the Party having the first right to control such Recall pursuant to
Section 5.10(b), and the other Party shall make available to the Party having
the first right to control such Recall all pertinent records which the Party
having the first right to control such Recall may reasonably request to assist
in effecting any Recall.
<PAGE>
            (B)   With respect to any clinical studies conducted by ViaCell
under this Agreement, ViaCell shall have the exclusive right to control a Recall
of any Cell Therapy Products in the Territory, and shall conduct such a Recall
at any time at which regulatory timeframes or public safety considerations so
require. Other than with respect to any clinical studies conducted by ViaCell
under this Agreement, Amgen shall have the exclusive right to control any Recall
of the Collaboration Products in the Territory, and shall conduct such a Recall
at any time at which regulatory timeframes or public safety considerations so
require. ViaCell and Amgen shall each maintain complete and accurate records of
any Recall it has the right to control pursuant to this Section 5.10 for such
periods as may be required by legal requirements, but in any event for no less
than [**].

      5.11  MANUFACTURING. ViaCell shall bear initial responsibility for
preparing communications to Regulatory Authorities relating to manufacturing
issues for Collaboration Products, subject to review by Amgen, and ViaCell shall
cooperate with Amgen with respect to other Regulatory Authority reporting,
communications and Regulatory Filings regarding the Collaboration Products.

      5.12  COMPLIANCE WITH LAWS AND REGULATIONS. To the extent applicable, each
Party agrees to maintain all regulatory and governmental permits, licenses and
approvals and to comply with all laws, rules and regulations that are applicable
to each such Party's activities and the particular stage of Development or
Commercialization of the Collaboration Products including, without limitation,
GLPs, GCPs and GMPs, as such standards are defined in accordance with the
applicable guidance and regulations including the International Conference of
Harmonization (ICH), the U.S. Food, Drug and Cosmetic Act, 21 C.F.R. Section
210, 312, 1271 et seq. and the regulations promulgated thereunder, and any
amendments thereto and the regulations promulgated thereunder, and the
equivalent laws, rules and regulations of other countries in the Territory.

                                    ARTICLE 6
                                COMMERCIALIZATION

      6.1   COMMERCIAL PLAN. Amgen shall be responsible for preparing and
submitting the Commercial Plan section of the Program Plan with respect to
Collaboration Products to and for approval by the JSC, and shall update the
Commercial Plan on an [**] basis, [**]; provided however, it is acknowledged and
agreed that the Commercial Plan may need to be modified from time to time based
upon commercial considerations including unanticipated events. [**].



[**] Portions of this exhibit have been omitted pursuant to a confidential
treatment request. An unredacted version of this exhibit has been filed with the
Commission.
<PAGE>
      6.2   RESPONSIBILITIES AND RIGHTS OF AMGEN. Amgen shall be the "Commercial
Lead" and be responsible for all aspects of Commercializing Collaboration
Product(s) in the Territory, including making all strategic and tactical
decisions with respect thereto. These activities shall include, without
limitation: (a) Commercial strategies (e.g., strategies for regulatory,
branding, product positioning, pre-launch, market research, launch and
post-launch marketing and promotion, pricing and reimbursement and field sales
force optimization); (b) packaging, labeling and language to be included in the
package insert; (c) forecasting sales and Commercial manufacturing production
requirements; (d) creating and developing Promotional Materials regarding
Collaboration Products which are intended for distribution to medical
professionals, other Third Parties and to the Parties' respective sales forces;
(e) Promotion; (f) Detailing, including setting sales force staffing levels and
Detailing levels; (g) sales and distribution, taking orders and distributing,
contracting, handling of returns, handling all aspects of order processing,
invoicing and collecting, warehousing, documenting inventory and receivables and
collecting prescription tracking, call reporting, handling data regarding sales
to hospitals and other end users and handling all other customer service-related
functions; (h) setting level of sampling; (i) selecting, obtaining and
maintaining generic names and Product Trademarks; (j) licensing or otherwise
acquiring rights to intellectual property from Third Parties; (k) supervising
and training of (and coordinating sales briefing meetings and disseminating
information, including all communications related to marketing and Promotion);
(l) establishing target call lists; (m) carrying out all aspects of conducting
all Post-Approval Clinical Studies; (n) preparing publications and presentations
of data regarding Collaboration Products and (o) establishing material transfer
agreements, clinical trial and other agreements, pursuant to Section 10.13. For
the avoidance of doubt, neither Party shall have any rights to commercialize
Cell Therapy Products and ViaCell reserves for itself all rights to
commercialize all Unoptioned Cell Therapy Products.

      6.3   MEDICAL AND OTHER INQUIRIES. Amgen shall have responsibility for all
correspondence and communication with physicians and other health care
professionals and customers in the Territory regarding Collaboration Product
complaints and all adverse drug experience information and all other
correspondence and communication with physicians and other health care
professionals and customers in the Territory relating to Collaboration Products.
Amgen shall keep such records and make such reports as shall be reasonably
necessary to document such communications in compliance with all applicable
regulatory requirements.

      6.4   PROMOTIONAL MATERIALS. Amgen shall be responsible for the creation,
preparation, production and reproduction of all Promotional Materials relating
to the Collaboration Products and for filing, as appropriate, such Promotional
Materials with all Regulatory Authorities.
<PAGE>
            (A)   To the extent permitted by law, regulation or Regulatory
Authorities, each Collaboration Product will be marketed as a joint product of
ViaCell and Amgen and references to ViaCell and ViaCell's logo shall be included
on all Product Labeling in a manner that is substantially similar in terms of
prominence and in all other respects as the references to Amgen and Amgen's logo
included in such Product Labeling and in a manner that complies with the terms
and conditions of this Agreement (including without limitation Section 10.5
hereof). Amgen shall use Commercially Reasonable Efforts in designing and
producing Promotional Materials to promote the Collaboration Products and shall
use Commercially Reasonable Efforts to use ViaCell's name and logo in such
Promotional Materials with reasonably similar prominence as Amgen's name and
logo, and pursuant to the terms of Section 6.4(b), shall consider in good faith
the comments and suggestions of ViaCell in relation to such Promotional
Materials, including with respect to the use of ViaCell's logo.

            (B)   Prior to the use thereof, Amgen shall provide to ViaCell a
prototype of any Promotional Materials or Product Labeling which contains
ViaCell's corporate name and/or logo, so that ViaCell may review the manner in
which its corporate name and/or logo are used therein. ViaCell shall notify
Amgen within [**] after delivery of such prototype, whether ViaCell approves or
disapproves of the manner of such use and, in the case of disapproval, the
specific reasons therefor and an acceptable alternative. In the event that
ViaCell fails to so notify Amgen within such [**] period, ViaCell shall be
deemed to have approved the manner of such use. In the event that (i) the
Promotional Materials and Product Labeling comply with Section 6.4(a), but
ViaCell disapproves of the manner of such use and (ii) the Parties are unable to
reach agreement regarding the manner of such use before an applicable regulatory
or other legal deadline for submission of Promotional Materials, then Amgen
shall retain the right to print and use, and ViaCell agrees to use, to the
extent applicable, such Promotional Materials and Product Labeling without
ViaCell's corporate name and/or logo. Amgen and ViaCell shall continue efforts
to reach agreement on approving Promotional Materials with ViaCell's corporate
name and/or logo that comply with Section 6.4(a).

            (C)   Compliance with Laws, Regulations and Guidelines. Each Party
agrees to comply with all applicable laws, rules and regulations (e.g., the FD&C
Act, the PHS Act, the U.S. Foreign Corrupt Practices Act and any amendments
thereto and the regulations promulgated thereunder, and the equivalent laws,
rules and regulations in the Territory) and in all material respects to conform
its practices and procedures with, as applicable, the Pharmaceutical Research
and Manufacturers of America ("PhRMA") Code of Pharmaceutical Marketing
Practices and the American Medical Association ("AMA") Guidelines on Gifts to
Physicians from Industry, as the same may be amended from time to time, and
equivalent guidelines in the Territory with respect to the Commercialization of
Collaboration Products. Each Party shall conduct its business operations and
cause each of its employees, representatives and agents to do nothing which such
Party knows or reasonably should know would jeopardize the good will or
reputation of the other Party or the Cell Therapy Products or Collaboration
Products. Neither Party shall be required to undertake any activity relating to
the Commercialization of Cell Therapy Products or Collaboration Products that it
believes, in good faith, may violate any law or regulations. Each Party shall
promptly notify the other Party of and provide to that other Party a copy of any
correspondence or other reports with respect to the Promoting or Detailing of
Collaboration Products submitted to or received from PhRMA or the AMA or
equivalent organizations in the Territory and Amgen shall be responsible for
responding to such correspondence or other



[**] Portions of this exhibit have been omitted pursuant to a confidential
treatment request. An unredacted version of this exhibit has been filed with the
Commission.
<PAGE>
reports. Each Party shall in all material respects conform its practices and
procedures relating to educating the medical community in the U.S. with respect
to Collaboration Products to the Accreditation Council for Continuing Medical
Education ("ACCME") Standards for Commercial Support of Continuing Medical
Education and any applicable FDA regulations or guidelines, as the same may be
amended from time to time, and, as applicable, equivalent guidelines in the
Territory and each Party shall promptly notify the other Party of and provide to
the other Party a copy of any correspondence or other reports submitted to or
received from the ACCME with respect to Collaboration Products and Amgen shall
be responsible for responding to such correspondence or other reports.

                                    ARTICLE 7
                             MANUFACTURE AND SUPPLY

      7.1   MANUFACTURING PLAN. Except as otherwise provided in this Agreement,
ViaCell shall be responsible for preparing and submitting the Manufacturing Plan
section of the Program Plan with respect to Cell Therapy Products and
Collaboration Products to and for approval by the JSC, and shall update the
Manufacturing Plan on an [**] basis, [**]; provided however, it is acknowledged
and agreed that the Manufacturing Plan may need to be modified from time to time
based upon commercial considerations including unanticipated events. [**].

      7.2   RESPONSIBILITIES AND RIGHTS OF VIACELL. Subject to Section 7.2(g),
ViaCell shall be the "Manufacturing Lead" and ViaCell shall be responsible for
manufacturing and supplying Cell Therapy Products and Collaboration Products for
Development and Commercialization in the Territory. Except as otherwise provided
in this Agreement, ViaCell shall have responsibility for all aspects of
manufacturing Collaboration Products(s) in the Territory, including making all
strategic and tactical decisions with respect to establishing the methods and
means by which it performs such services and fulfills its regulatory
responsibilities over all steps of the manufacturing process. These activities
include, without limitation, bulk manufacture, finish and fill, labeling and
packaging, lot release and process development work to support quality
assurance, improving manufacturing/cost efficiency and commercial scale-up
manufacturing.

            (a)   Manufacture of Cell Therapy Products for Development. With
respect to each Cell Therapy Product selected to be advanced to IND-enabling
toxicology studies and/or clinical studies, ViaCell shall use its Commercially
Reasonable Efforts to develop and initiate scale-up of the manufacturing
process, to develop a manufacturing process(es) suitable for commercial
production, and to supply clinical grade, filled and finished, selected Cell
Therapy Products for use in all pre-clinical trials and clinical trials in the
Territory, in quantities and with specifications sufficient to support the
required studies.



[**] Portions of this exhibit have been omitted pursuant to a confidential
treatment request. An unredacted version of this exhibit has been filed with the
Commission.
<PAGE>
            (b)   Manufacture of Collaboration Product(s) for Commercialization.
With respect to each Collaboration Product, ViaCell shall use its Commercially
Reasonable Efforts to supply filled and finished Collaboration Products approved
by each applicable Regulatory Authority for commercial use in the Territory, in
quantities (as reasonably forecast by Amgen) and with specifications consistent
with the Collaboration Product. Amgen shall determine its good faith projected
Collaboration Product supply needs, taking into consideration inventory levels,
and will deliver an annual rolling forecast, updated quarterly.

            (c)   Standards of Supply. ViaCell will use its Commercially
Reasonable Efforts to manufacture Cell Therapy Products and Collaboration
Products in accordance with current GMP in a manufacturing process and facility
as described in the applicable Regulatory Filings filed with the Regulatory
Authority. ViaCell shall be responsible for the labeling, packaging and lot
release of Collaboration Products it manufactures or has manufactured. ViaCell
shall be responsible for the quality assurance/quality control (QA/QC) of all
Collaboration Products manufactured by or for it and shall provide a
certification that all supplied Collaboration Products shall conform to the
product specifications.

            (d)   Manufacturing Cost and Budget. [**]. For Commercial
Collaboration Products, [**] shall be estimated and established [**] . Within
[**] following the end of ViaCell's fiscal year, ViaCell shall compare its
actual annual [**] for the prior year calculated using the [**] amount (vials
manufactured multiplied by [**] per vial, excluding any annual adjustment
related to the previous year, but including any interim adjustment charged to
Amgen as described below). ViaCell shall use this annual adjustment to
increase/decrease the [**] for the then-current Calendar Year in order to
recover/refund this difference from/to the Parties. The per unit annual
adjustment to the [**] shall be based upon the forecasted annual requirements
(as included in the rolling forecast to be supplied by the Commercial Lead on a
quarterly basis) for such following year. Until the annual adjustment is
calculated, ViaCell shall estimate the annual adjustment to be included in the
following year's [**] in good faith. If the rolling forecast volume over the
next [**] to be supplied to the Commercial Lead decreases by more than [**]
compared to the previously submitted rolling forecast, [**] for the year will be
recalculated. If, based upon such recalculation, ViaCell determines that [**]
has increased, an interim adjustment shall be made to [**] and such interim
adjustment will apply to all Commercial Collaboration Products supplied for the
remainder of the year on a Collaboration Product-by-Collaboration Product basis.
ViaCell will give Amgen [**] written notice prior to applying the interim
increase in [**]



[**] Portions of this exhibit have been omitted pursuant to a confidential
treatment request. An unredacted version of this exhibit has been filed with the
Commission.
<PAGE>
            (e)   Third Party Licenses.

                  (I)   [**] deems necessary for a license or other rights or to
incur an obligation to make payments to any Third Parties in return for a
license to Third Party Patent Rights and other intellectual property rights
necessary or useful to make or have made Collaboration Product in any country in
the Territory, for subsequent use, sale or other exploitation or transfer of
physical possession of or title in a Collaboration Product in the Territory.
[**] shall have the right to incorporate Third Party payments made to any Third
Party within the [**] as set forth in Exhibit B, provided however that prior to
entering into any such agreement, [**] shall provide to [**] a summary of the
subject matter of the proposed license and the proposed financial terms and
consider in good faith any comments or suggestions [**] may timely provide in
relation thereto. In the event that ViaCell becomes aware of any Third Party
intellectual property rights that ViaCell believes in good faith would be
necessary or useful in connection with the manufacturing or Commercialization of
Collaboration Products, ViaCell shall identify such Third Party intellectual
property rights to Amgen and the parties shall discuss in good faith whether
obtaining a license would be beneficial.

                  (II)  [**] deems necessary for a license or other rights or to
incur an obligation to make payments to any Third Parties in return for a
license to Third Party Patent Rights and other intellectual property rights
necessary or useful to make or have made Cell Therapy Product(s) in any country
in the Territory, for subsequent use, sale or other exploitation or transfer of
physical possession of or title in a Cell Therapy Product in the Territory. [**]
shall have the right to incorporate Third Party payments made to any Third Party
within the [**] as set forth in Exhibit B, provided however that prior to
entering into any such agreement, [**] shall provide to [**] a summary of the
subject matter of the proposed license and the proposed financial terms and
consider in good faith any comments or suggestions [**] may timely provide in
relation thereto. In the event that Amgen becomes aware of any Third Party
intellectual property rights that Amgen believes in good faith would be
necessary or useful in connection with the manufacturing or future
Commercialization of Cell Therapy Products, Amgen shall identify such Third
Party intellectual property rights to ViaCell and the Parties shall discuss in
good faith whether obtaining a license would be beneficial. Notwithstanding the
foregoing, ViaCell may not obtain a license to Third Party Patent Rights to make
or have made a Cell Therapy Product without the prior written consent of Amgen
if the license requires ViaCell to pay, on a product-by-product basis a
percentage-based royalty that exceeds (A) [**] or (B) together with all other
percentage-based royalties owed to Third Parties for licenses to make or have
made such Cell Therapy Products entered into by ViaCell without Amgen's prior
written consent, [**].

            (F)   Supply Performance. In the event that ViaCell does not
exercise Commercially Reasonable Efforts to perform its duties as Manufacturing
Lead for a Collaboration Product, Amgen [**] upon written notice to ViaCell.
[**], a Manufacturing Transition shall be initiated. For the avoidance of doubt,
ViaCell shall be deemed to have not exercised Commercially Reasonable Efforts
upon the occurrence of any of the following events (except to the extent that
such events are the direct result of Amgen's failure to supply Contributed
Products in accordance with the terms and conditions of this Agreement):

                  (I)   [**];

                  (II)  [**];

                  (III) [**]; and

                  (IV)  [**];



[**] Portions of this exhibit have been omitted pursuant to a confidential
treatment request. An unredacted version of this exhibit has been filed with the
Commission.
<PAGE>
provided however that Amgen may not have the right to effect a Manufacturing
Transition as a result of any of these failures, unless Amgen has given ViaCell
prior written notice of such failure and ViaCell has not cured such failure
within [**]of the receipt of such notice. Amgen's right to assume the rights and
responsibilities of Manufacturing Lead is in addition to and does not relieve
the Parties of any rights or responsibilities under this Agreement.

            (G)   Manufacturing Transition.

                  (I)   Upon Amgen providing a written notice to ViaCell of
Amgen exercising its rights to assume the rights and obligations of the
Manufacturing Lead pursuant to Section 7.2(f) or 4.6 with respect to a
Collaboration Product (a "Manufacturing Transition Notice"), ViaCell shall
promptly provide to Amgen all information, Materials and ViaCell Know-How as may
be useful or necessary to facilitate Amgen's manufacture of that Collaboration
Product.

                  (II)  Upon delivering a Manufacturing Transition Notice to
ViaCell, the JSC shall no longer have any rights or obligations with respect to
the Collaboration Product that is the subject of such manufacturing Transition
Notice, and Amgen shall have sole decision making authority with respect to all
aspects of such Collaboration Product, including the Development, manufacturing
and Commercialization of such Collaboration Product, without any obligation to
discuss information with or disclose information to ViaCell (other than
information relating to Operating Profit or Loss for such Collaboration Product,
including without limitation the information described in Section 9.2 hereof),
[**].

                  (III) ViaCell and Amgen shall [**].

      7.3   MANUFACTURE OF CONTRIBUTED PRODUCTS. Except as otherwise explicitly
provided below, Amgen will have the sole right and responsibility to manufacture
Contributed Products in accordance with the supply obligations set forth below.
At Amgen's sole discretion, Amgen may decide to transfer manufacturing
responsibility for a Contributed Product to a third party manufacturer,
including but not limited to a contract manufacturer.

            (A)   Supply Terms.

                  (I)   Subject to Section 7.3(a)(ii) below, Amgen shall supply
Contributed Products to ViaCell and any Sublicensees in reasonable quantities,
as requested by ViaCell or such Sublicensees from time to time.

                  (II)  Amgen shall only be obligated to supply Contributed
Products from readily available inventory on an as-available basis and in the
filled and finished form of Amgen's existing inventory, and Amgen shall not, for
any reason or under any circumstance, be obligated to manufacture Contributed
Products for the purpose of supplying Contributed Products to ViaCell or any
Sublicensees. Prior to the Transition Date, ViaCell shall pay Amgen [**] per
vial of Flt3-L supplied, [**] per vial of SCF supplied, and for any other
Contributed Products, a price to be agreed by the Parties prior to ViaCell
accepting such product as a Contributed Product. After the Transition Date,
ViaCell shall pay Amgen a price equal to [**].



[**] Portions of this exhibit have been omitted pursuant to a confidential
treatment request. An unredacted version of this exhibit has been filed with the
Commission.
<PAGE>
            (B)   cGMP and Specifications. Where required, Contributed Products
supplied by Amgen hereunder shall be manufactured in accordance with current
Good Manufacturing Practices (as defined in the United States Code of Federal
Regulations) and the manufacturing process approved by relevant Regulatory
Authorities, and shall at least conform to the current specifications as of the
Effective Date, a copy of which has been provided to ViaCell. Amgen shall
promptly notify ViaCell of any changes to the specifications of Contributed
Products.

            (C)   No Transfer of Manufacturing Know-How. Amgen shall have no
obligation for any reason or under any circumstance, to provide ViaCell or any
Third Party with any information or materials regarding Amgen's know-how related
to the manufacturing of Contributed Products. Subject to the foregoing, in the
event that Amgen is unable or unwilling to supply ViaCell's or any Sublicensee's
requirements of Contributed Products in accordance with the terms and conditions
of this Agreement, including as a result of a Force Majeure, Amgen shall grant
to ViaCell a non-exclusive license under the Amgen Patent Rights to make or have
made (under contract with no more than two (2) Third Parties, who shall be
permitted under such contract(s) solely to supply Contributed Products
exclusively to ViaCell and any Sublicensees) and import ViaCell's and any
Sublicensee's requirements of Contributed Products for the sole purpose of
practicing ViaCell's and any Sublicensee's rights under the non-exclusive
license as set forth in Section 10.2.

            (D)   Demand Forecasts. ViaCell shall provide Amgen a written report
containing a forecasted estimate of the following Calendar Year's requirements
of Contributed Products. The report will include monthly requirements for each
SKU (Stock Keeping Unit) and will be delivered in the prior Calendar Year in
time to meet Amgen's budget timeline. Updates to the forecast shall be provided
in writing to Amgen [**] prior to the beginning of each [**].

            (E)   Orders. ViaCell and any Sublicensees shall specify by binding
written firm purchase order its or their reasonable requirements of Contributed
Products not later than [**] prior to ViaCell's or such Sublicensees' requested
delivery date. Each binding firm purchase order shall specify the quantity of
vials (or other relevant unit) of Contributed Products and the requested
delivery date. Subject to the terms of Section 7.2(a) above, Amgen shall supply
Contributed Products to ViaCell and any Sublicensees on the requested delivery
date in response to any such written firm purchase order.

            (F)   Shipment and Delivery. All Contributed Products supplied by
Amgen to ViaCell shall be delivered to ViaCell Ex Works ("EXW") (IncoTerms 2000)
a designated Amgen manufacturing facility. ViaCell shall be responsible for all
delivery logistics, delivery validation, insurance and compliance with laws and
regulations (including but not limited to those applicable to the export of each
EXW delivery from the United States to destinations outside the United States)
and all costs associated with the foregoing. Title to each EXW delivery and risk
of damage or loss shall pass to ViaCell immediately after leaving Amgen's
designated facility.

            (G)   Release of Licensed Product. Amgen shall be responsible for
the final release of Contributed Product.



[**] Portions of this exhibit have been omitted pursuant to a confidential
treatment request. An unredacted version of this exhibit has been filed with the
Commission.
<PAGE>
            (H)   Statements and Payments. For Contributed Products shipped
prior to the Transition Date, Amgen shall, on an as-delivered basis, provide
ViaCell with an invoice setting forth the quantities of Contributed Products
delivered to ViaCell and the supply price. Payments shall be due from ViaCell
within [**] following ViaCell's receipt of an invoice. ViaCell shall pay all
applicable excise, sales or other transfer taxes assessed on the supply of
Contributed Products hereunder. Delivery costs shall be paid directly by ViaCell
to its designated carrier. Any sums not paid when due are subject to a service
charge of [**] per month or the maximum rate permitted by law, whichever is
lower. [**].

      7.4   LIMITATION ON APPLICATION OF SUPPLY TERMS. The provisions in this
Agreement governing per vial price apply solely in the context of this agreement
and are not meant to be effective independent from the terms contained herein.

                                    ARTICLE 8
                           COLLABORATION CONSIDERATION

      8.1   LICENSE FEE. The parties recognize that, pursuant to the terms and
conditions set forth in the License Agreement by and between ViaCell and Amgen
dated April 9, 2002 and related Warrant Purchase Agreement, ViaCell issued Amgen
a warrant to purchase 560,000 shares of common stock of ViaCell as partial
consideration for a non-exclusive license to SCF set forth therein.

      8.2   MILESTONE PAYMENTS. For each Collaboration Product, Amgen shall pay
ViaCell a [**] one-time milestone payment via wire transfer to an account
designated by ViaCell within [**] following the achievement of the first
Regulatory Approval of the first indication in the U.S. for such Collaboration
Product. For the avoidance of doubt, changes in presentation, formulation,
delivery or dosage form shall not trigger a payment obligation under this
Section 8.2

      8.3   RELATED AGREEMENTS. The Parties hereby acknowledge and agree that
concurrently with entering into this Agreement the parties are also entering
into that certain Securities Purchase Agreement and certain ancillary agreements
relating thereto, each of even date herewith.

                                    ARTICLE 9
                     PROGRAM PLAN; OPERATING PROFIT OR LOSS

      9.1   OPERATING PROFIT OR LOSS SHARING. On and after the Transition Date,
Amgen and ViaCell shall each share on a [**] basis the Operating Profit or Loss
for all Collaboration Products.



[**] Portions of this exhibit have been omitted pursuant to a confidential
treatment request. An unredacted version of this exhibit has been filed with the
Commission.
<PAGE>
      9.2   ACCOUNTING AND REPORTING OF COLLABORATION PROFITS AND LOSSES.

            (A)   [**] after the end of each Calendar Quarter after the first
Transition Date, the Parties shall each submit to the other Party a written
report (including supporting documentation) setting forth in reasonable detail
an accounting of any Net Sales and Allowed Expenditures (as defined in Exhibit
B) that have been incurred during the most recent Calendar Quarter.

            (B)   After the first Transition Date, Amgen shall establish and
maintain an accounting of the Net Sales and Allowed Expenditures in the
Operating Profit or Loss account in accordance with the terms of Exhibit B.
Within [**] following the end of each Calendar Quarter, Amgen shall submit to
ViaCell a written report setting forth in reasonable detail (and including
supporting documentation) an accounting of all items credited or charged to the
Operating Profit or Loss account and the calculation of any net amount owed by
ViaCell to Amgen or by Amgen to ViaCell, as the case may be, in order to ensure
the appropriate [**] sharing of Operating Profit or Loss. The net amount payable
(taking into account each Party's [**] charged to the Operating Profit or Loss
in accordance with the terms of this Agreement and Exhibit B) shall be paid by
Amgen or ViaCell, as the case may be, within [**] after receipt of such written
report, without regard to any dispute as to the amounts under this Section
9.2(b). With the exception of [**] and [**], neither Party may charge expenses
to the Operating Profit or Loss account for [**].

            (C)   In the event of a dispute with respect to any amounts under
Sections 9.2(a) or 9.2(b), the disputing Party shall provide written notice
within [**] after receipt of the written report in question, specifying such
dispute and explaining the basis of the dispute. The Parties shall promptly
thereafter meet and negotiate in good faith a resolution to such dispute. In the
event that the Parties are unable to resolve such dispute within [**] after
notice by the disputing Party, the matter shall be resolved in a manner
consistent with the procedures set forth in Article 17.

            (D)   ViaCell and Amgen shall work in good faith to realize the
benefits of federal and state tax incentives and credits including orphan drug
credits pursuant to IRC Section 41 and Section 45C for the activities or
expenditures of either Party under this Agreement or any legal entity formed
pursuant to Section 14.2(f) of this Agreement.

            (E)   Upon termination of this Agreement, the Parties shall
immediately (but in no event any later than [**] from such termination) conduct
a final accounting to reconcile, settle and close the Operating Profit or Loss
account; provided however, that after such final accounting, with respect to
surviving sections that reference the charging or crediting of the Operating
Profit or Loss account, such charges or credits shall be made directly between
the Parties and shall proportionally borne by the Parties in the same manner as
if such Operating Profit or Loss account was still open.

                                   ARTICLE 10
                              INTELLECTUAL PROPERTY

      10.1  TECHNOLOGY OWNERSHIP. Except as otherwise provided below in this
Agreement, ownership of inventions shall be determined in accordance with the
rules of inventorship under



[**] Portions of this exhibit have been omitted pursuant to a confidential
treatment request. An unredacted version of this exhibit has been filed with the
Commission.
<PAGE>
United States patent laws. Amgen shall own all right, title and interest in and
to Amgen Technology, and any Confidential Information contained therein shall be
considered the Confidential Information of Amgen. ViaCell shall own all right,
title and interest in and to ViaCell Technology, and any Confidential
Information contained therein shall be considered the Confidential Information
of ViaCell. All right, title and interest in and to Joint Know-How (which shall
be considered the joint Confidential Information of the Parties) and Joint
Patent Rights shall be owned, as between the Parties, jointly by ViaCell and
Amgen. Each Party shall have the unrestricted, royalty-free, worldwide right to
make, have made, use, sell, lease, offer to sell or lease, import, export or
otherwise exploit, or transfer physical possession of or title in Joint Know-How
and the subject matter of the Joint Patent Rights, without accounting. All
rights, title and interest in and to Product Trademarks shall be owned by Amgen.

      10.2  CONTRIBUTED PRODUCT LICENSES; SUBLICENSE RIGHTS.

            (A)   LICENSE. Amgen hereby grants to ViaCell a fully paid-up,
royalty-free, non-exclusive license, with no right to grant sublicenses except
pursuant to Section 10.2(b), under the Amgen Technology solely to use
Contributed Products in the Territory for the purpose of (i) making, having made
(solely in accordance with Section 18.6), using, selling, having sold, offering
to sell, having offered for sale, importing, having imported, exporting or
otherwise transferring physical possession of or otherwise transferring title in
either or both of Cell Therapy Products or Unoptioned Cell Therapy Products and
(ii) making and having made Collaboration Products. For the avoidance of doubt,
except as provided in Section 7.3(c), ViaCell shall not have the right to make
or have made any Contributed Products, and under no circumstance shall ViaCell
have the right to sell, offer for sale or import any Contributed Products.

            (B)   SUBLICENSES. Subject to the other terms and conditions of this
Agreement, ViaCell may only grant sublicenses in connection with a subcontract
permitted in accordance with Section 18.6 below or the assignment of rights to a
Collaboration Product or an Unoptioned Cell Therapy Product in accordance with
Section 4.6 above, and sublicenses granted shall be permitted solely to the
extent consistent with the license provided in Section 10.2(a). For a sublicense
to be valid, the sublicensee under any sublicense permitted under the previous
sentence (the "ViaCell Sublicensee") must in advance execute a written
sublicense agreement between ViaCell and the applicable ViaCell Sublicensee
("ViaCell Sublicense Agreement(s)") which contains the applicable terms and
conditions of this Agreement, including without limitation terms and conditions
regarding the purchase of the Contributed Products from Amgen which are
substantially the same as the terms and conditions set forth in Article 7 of
this Agreement. Each ViaCell Sublicense Agreement shall provide that Amgen shall
be a third-party beneficiary of the provisions of such agreement. ViaCell shall
promptly notify Amgen upon learning of any breach of any provision of a ViaCell
Sublicense Agreement, and either (i) [**] enforce the terms of such ViaCell
Sublicense Agreement or (ii) [**] permit Amgen to enforce such terms or
conditions in its own right and ViaCell shall reasonably cooperate in such
enforcement. Sublicensees shall not be permitted to grant any further
sublicenses under the Amgen Technology.



[**] Portions of this exhibit have been omitted pursuant to a confidential
treatment request. An unredacted version of this exhibit has been filed with the
Commission.
<PAGE>
      10.3  COLLABORATION PRODUCT LICENSE; SUBLICENSE RIGHTS.

            (A)   LICENSE. ViaCell hereby grants to Amgen a fully paid-up,
royalty-free, exclusive license, with no right to grant sublicenses except
pursuant to Section 10.3(b), under the ViaCell Technology to use, sell, offer to
sell, import, export or otherwise transfer physical possession of or otherwise
transfer title in Collaboration Products in the Territory, solely in compliance
with the terms and conditions of this Agreement. In addition, effective only
upon a Manufacturing Transition, ViaCell hereby grants to Amgen a fully paid-up,
royalty-free, non-exclusive license, including the right to sublicense, under
the ViaCell Technology to make and have made the applicable Collaboration
Product in the Territory, solely in compliance with the terms and conditions of
this Agreement.

            (B)   SUBLICENSES. Subject to the other terms and conditions of this
Agreement, Amgen may grant sublicenses (solely to the extent consistent with the
license provided in Section 10.3(a)) under the ViaCell Technology; provided that
the sublicensee under any such permitted sublicense (the "Amgen Sublicensee")
expressly agrees to be bound by a written sublicense agreement between Amgen and
the applicable Amgen Sublicensee ("Amgen Sublicense Agreement(s)") which
contains the applicable terms and conditions of this Agreement. Each Amgen
Sublicense Agreement shall provide that ViaCell shall be a third-party
beneficiary of the provisions of such agreement. Amgen shall promptly notify
ViaCell upon learning of any breach of any provision of an Amgen Sublicense
Agreement, and either (i) [**] enforce the terms of such Amgen Sublicense
Agreement or (ii) [**] permit ViaCell to enforce such terms or conditions in its
own right and Amgen shall reasonably cooperate in such enforcement. Sublicensees
shall not be permitted to grant any further sublicenses under the ViaCell
Technology.

      10.4  PASS THROUGH RESTRICTIONS. Certain license rights granted to a Party
under this Article 10 may include a sublicense of Patent Rights and know-how of
Third Parties under Third Party licenses. Notwithstanding anything to the
contrary in this Agreement, the Party receiving a sublicense of such Third Party
licenses shall, in exercising such sublicense rights, comply with, perform in
accordance with, and be subject to the provisions of such Third Party licenses
relating to Contributed Products or Collaboration Products if the granting Party
has provided a copy of such Third Party license to the Party receiving a
sublicense of such Third Party licenses. Each Party shall promptly provide to
the other Party a copy of any notice of breach received by it under any such
Third Party license.



[**] Portions of this exhibit have been omitted pursuant to a confidential
treatment request. An unredacted version of this exhibit has been filed with the
Commission.
<PAGE>
      10.5  TRADEMARK LICENSE.

            (A)   ViaCell hereby grants to Amgen a nonexclusive, royalty-free
license, including the right to grant sublicenses to Amgen Sublicensees in
connection with a sublicense of the rights granted under Section 10.3 above,
under ViaCell Trademarks to use and display the ViaCell Trademarks in connection
with Collaboration Products in the Territory solely in compliance with the terms
and conditions of this Agreement; provided, however, that, in connection with
any sublicense of the rights granted in this Section 10.5(a), the applicable
Amgen Sublicense Agreement shall contain terms and conditions substantially the
same as this Section 10.5.

            (B)   Amgen acknowledges ViaCell's exclusive ownership of the
ViaCell Trademarks and that use of any of the ViaCell Trademarks by Amgen shall
inure to the sole benefit of ViaCell. Amgen shall not do or suffer to be done
any act or thing inconsistent with such ownership and shall not acquire or claim
or assist third parties in acquiring or claiming any title in or to any of the
ViaCell Trademarks by virtue of this Agreement or through Amgen's use of the
ViaCell Trademarks. In addition, Amgen hereby covenants that it shall not
directly or indirectly undertake any action that in any manner might question,
contest, challenge, infringe or impair the validity, enforceability, scope of
rights or title of ViaCell in any of the ViaCell Trademarks at any time during
the term of this Agreement and thereafter.

            (C)   Amgen shall use the ViaCell Trademarks only in a manner and
form: (i) designed to maintain the high quality of the ViaCell Trademarks; (ii)
consistent with the use of the ViaCell Trademarks by ViaCell; (iii) that
protects ViaCell's ownership interest therein; and (iv) that complies with all
applicable federal, state, local and foreign laws, rules and regulations,
including without limitation all applicable trademark laws, rules and
regulations.

            (D)   During the term of this Agreement and thereafter, Amgen shall
not adopt or use any word, name, mark, symbol, other designation or trade style
which in ViaCell's sole reasonable opinion is likely to cause confusion or
dilute any of the ViaCell Trademarks, and shall not make any unlicensed use of
trademarks or service marks which, in ViaCell's sole reasonable opinion, is
confusingly similar to or dilutive of any of the ViaCell Trademarks. In
addition, Amgen agrees that it shall not use any of the ViaCell Trademarks in
combination with any word, name, mark, symbol, other designation or trade style
so as to create a composite mark, unless such use is explicitly authorized in
writing by ViaCell.

            (E)   Amgen agrees and undertakes that all Collaboration Products
identified by any of the ViaCell Trademarks shall be at least equal in quality
to the mutually agreed specifications therefor (the "Quality Standard"). To the
extent that a Manufacturing Transition has been triggered, ViaCell shall have
the right no more than [**] to request a reasonable number of samples of the
Collaboration Product for the sole purpose of auditing the quality of such
Collaboration Product to determine whether such Collaboration Products meet the
Quality Standard. Should ViaCell notify Amgen that a Collaboration Product
identified by any of the ViaCell Trademarks fails to comply with the Quality
Standard in effect at that time, Amgen shall correct such defects in accordance
with such reasonable notification from ViaCell within [**] of such notice.



[**] Portions of this exhibit have been omitted pursuant to a confidential
treatment request. An unredacted version of this exhibit has been filed with the
Commission.
<PAGE>
            (F)   ViaCell shall have the right to audit and inspect, upon
advance written notice and during regular business hours, Amgen's use of
Trademarks licensed hereunder.

      10.6  PROSECUTION.

            (A)   (I) Amgen shall be solely responsible for and have complete
discretion with respect to (using the firm of [**] or such other mutually
acceptable outside counsel) the filing, prosecution, defense and maintenance of
the Amgen Patent Rights before all patent authorities in the Territory.

                  (II)  Amgen shall be responsible for (using the firm of [**]
or such other mutually acceptable outside counsel) the filing, prosecution,
defense and maintenance of the Joint Patent Rights before all patent authorities
in the Territory.

                  (III) ViaCell shall have the right to review and comment on
the filing, prosecution and defense by Amgen of the Joint Patent Rights. To that
end, Amgen shall instruct such outside counsel to furnish ViaCell with a
reasonably complete draft of each submission to a patent authority materially
affecting Joint Patent Rights no later than [**] prior to the date such
submission is proposed to be made, or if given less than [**] to respond as soon
as practicable, and Amgen will reasonably consider any of ViaCell's reasonably
timely comments thereon. Additionally, Amgen shall instruct its outside counsel
to provide ViaCell with a copy of each submission made to and document received
from a patent authority materially affecting any Joint Patent Rights reasonably
promptly after making such filing or receiving such document. If Amgen
determines in its sole discretion to not file, prosecute, defend or maintain any
patent application or patent within the Joint Patent Rights in any country, then
Amgen shall provide ViaCell with [**] prior written notice of such determination
and shall provide ViaCell with the right and opportunity to file, prosecute,
defend and maintain such patent application or patent on behalf of Amgen.

            (B)   (I) ViaCell shall be responsible for the filing, prosecution,
defense and maintenance of ViaCell Patent Rights before all patent authorities
in the Territory, provided, however, that ViaCell shall do so using mutually
reasonably acceptable outside counsel. As of the Effective Date, Amgen agrees
that [**] are reasonably acceptable outside counsel, provided however that Amgen
reserves the right to re-evaluate such outside counsel in future.



[**] Portions of this exhibit have been omitted pursuant to a confidential
treatment request. An unredacted version of this exhibit has been filed with the
Commission.
<PAGE>
                  (II)  Amgen shall have the right to review and comment on such
filing, prosecution and defense by ViaCell of the ViaCell Patent Rights. To that
end, ViaCell shall instruct such outside counsel to furnish Amgen with a
reasonably complete draft of each submission to a patent authority materially
affecting ViaCell Patent Rights no later than [**] prior to the date such
submission is proposed to be made, or if given less than [**] to respond as soon
as practicable, and ViaCell will reasonably consider any of Amgen's reasonably
timely comments thereon. Additionally, ViaCell shall instruct its outside
counsel to provide Amgen with a copy of each submission made to and document
received from a patent authority materially affecting any ViaCell Patent Rights
reasonably promptly after making such filing or receiving such document. If,
after the Transition Date for a Collaboration Product, ViaCell determines in its
sole discretion to not file, prosecute, defend or maintain any patent
application or patent within the ViaCell Patent Rights having at least one valid
and enforceable claim covering the composition, manufacture or use of that
Collaboration Product in any country, then ViaCell shall provide Amgen with [**]
prior written notice of such determination and shall provide Amgen with the
right and opportunity to file, prosecute, defend and maintain such patent
application or patent on behalf of ViaCell.

            (C)   Amgen and ViaCell shall cooperate with each other and render
all reasonable assistance in prosecuting and maintaining all intellectual
property licensed under this Agreement. Both Parties shall meet regularly, but
not less than on a [**] basis, to discuss the prosecution (and other related
proceedings, such as interferences and oppositions) of all intellectual property
licensed under this Agreement. Amgen and ViaCell shall cooperate with each other
in any such matters, and shall sign any necessary legal papers and provide the
Party responsible for such prosecution with data or other information in support
thereof (and use their best efforts to ensure the cooperation of any of their
respective personnel, Affiliates and licensee(s) as might reasonably be
requested).

            (D)   Amgen shall be responsible (using [**] or other mutually
acceptable outside counsel) for the filing, prosecution, defense and maintenance
of the Product Trademarks before all trademark authorities in the Territory.

            (E)   ViaCell hereby covenants that prior to preparing, filing or
taking any step in the prosecution of any patent claims that cover the
compositions-of-matter or use of any Contributed Product(s), it will seek and
use its best efforts to accommodate Amgen's, and its patent counsel's, comments
regarding such patent claims and any disclosure supporting such patent claims.
To the extent that ViaCell breaches its covenant in the immediately preceding
sentence, upon Amgen's request ViaCell shall promptly assign to Amgen all
rights, title and interest in all patent applications and issued patents that
cover the compositions-of-matter or uses of any Contributed Product(s).



[**] Portions of this exhibit have been omitted pursuant to a confidential
treatment request. An unredacted version of this exhibit has been filed with the
Commission.
<PAGE>

      10.7 INFRINGEMENT OF PATENT RIGHTS AND PRODUCT TRADEMARKS.

            (A) After the Transition Date for a Collaboration Product, Amgen
may, but shall not be obligated to, elect to enforce ViaCell Patent Rights
having at least one valid and enforceable claim covering the composition,
manufacture or use of that Collaboration Product and rights in ViaCell Know-How
against any actual, alleged or threatened infringement by Third Parties and to
defend such ViaCell Patent Rights and ViaCell Know-How against any challenges in
the Territory. In the event that Amgen shall so elect, Amgen shall seek and
reasonably consider ViaCell's comments before determining the strategy and
ViaCell shall reasonably assist and cooperate in any such enforcement or
defense.

            (B) In the event Amgen does not commence an enforcement and/or
defense action pursuant to this Section 10.7 within [**] after Amgen is notified
by ViaCell in writing of an infringement of ViaCell Patent Rights in the
Territory (or of the filing of a declaratory judgment action), ViaCell shall be
entitled to bring and prosecute such an action. If ViaCell elects to bring and
prosecute such an action, then ViaCell shall seek and reasonably consider
Amgen's comments on strategy.

            (C) Amgen may, but shall not be obligated to, enforce the Product
Trademarks against any actual, alleged or threatened infringement by Third
Parties or from any unfair trade practices, trade dress imitation, passing off
of counterfeit goods or like offenses. In the event that Amgen shall so elect,
Amgen shall seek and reasonably consider ViaCell's comments before determining
the strategy and ViaCell shall reasonably assist and cooperate in any such
enforcement or defense.

            (D) The Party bringing suit under this Section 10.7 shall be [**] to
carry out the activities described in this Section 10.7; and each Party shall
[**] described in this Section 10.8. Recoveries in any actions under this
Section 10.7 shall [**].

      10.8 INFRINGEMENT OF THIRD PARTY RIGHTS.

            (A) Amgen shall have the exclusive right, but shall not be
obligated, to defend any actual, alleged or threatened claim or action which
names Amgen and/or both Parties and which claims (i) the infringement of Third
Party Patent Rights or other intellectual property rights through the making,
having made, using, selling, offering to sell, importing exporting or otherwise
transferring physical possession of or otherwise transferring title in a
Collaboration Product or (ii) that a Product Trademark infringes any Third Party
trade name, service mark, logo or trademark. If necessary, ViaCell will assist
and cooperate with Amgen in any such defense. If Amgen does not defend such
claim or action, then ViaCell has the right, but shall not be obligated, to
defend such claim or action.

[**] Portions of this exhibit have been omitted pursuant to a confidential
treatment request. An unredacted version of this exhibit has been filed with the
Commission.
<PAGE>
            (B) ViaCell shall have the exclusive right, but shall not be
obligated, to defend any actual, alleged or threatened claim or action which
names ViaCell but does not name Amgen, and which claims the infringement of (i)
Third Party Patent Rights or other intellectual property rights through the
making, having made, using, selling, offering to sell, importing exporting or
otherwise transferring physical possession of or otherwise transferring title in
a Collaboration Product or (ii) any Third Party trade name, service mark, logo
or trademark. If necessary, Amgen will assist and cooperate with ViaCell in any
such defense.

            (C) A Party defending a suit pursuant to this Section 10.8 shall be
[**] described in this Section 10.8; and each Party shall [**] described in this
Section 10.8. Losses in any actions under this Section 10.8 shall [**].

      10.9 COOPERATION.

            (A) Each Party shall promptly notify the other upon becoming aware
of (i) any actual, alleged or threatened Third Party claim or action against
ViaCell and/or Amgen that a Contributed Product, Cell Therapy Product or
Collaboration Product infringes any Third Party intellectual property right; or
(ii) any Third Party infringement or misappropriation of the Amgen Patent
Rights, rights in Amgen Know How, ViaCell Patent Rights having at least one
valid and enforceable claim covering the composition, manufacture or use of a
Collaboration Product or rights in ViaCell Know How, (iii) any actual, alleged
or threatened Third Party claim or action against ViaCell and/or Amgen that a
Product Trademark infringes any Third Party trade name, service mark, logo or
trademark; or (iv) any Third Party infringement of the Amgen Trademarks, ViaCell
Trademarks that are applied to or used with Collaboration Products or any
Promotional Materials, Product Trademarks, Amgen Patent Rights, Amgen Know-How,
ViaCell Patent Rights having at least one valid and enforceable claim covering
the composition, manufacture or use of a Collaboration Product, ViaCell
Know-How, Joint Patent Rights or Joint Know-How.

            (B) The Parties shall confer with each other regarding the bringing
or defense of any suit under Section 10.7 and/or 10.8 including, if necessary
(and at each Party's own expense), assisting and cooperating with the other
Party in any such suit. If the Party bringing or defending such suit finds it
necessary or desirable to join the other Party as a party, the other Party shall
execute all papers or perform such other acts as may reasonably be required by
the Party bringing or defending such suit.

            (C) Neither Party shall enter into any settlement of any suit
brought or defended under Section 10.7 and/or 10.8 that affects the other
Party's rights or interests without such other Party's written consent, which
consent shall not be unreasonably withheld or delayed.

            (D) A Party bringing or defending suit under Section 10.7 and/or
10.8 shall notify the other Party of all substantive developments with respect
to such enforcement or defensive actions including, but not limited to, all
material filings, court papers and other related documents, substantive
settlement negotiations and offer of settlement.

[**] Portions of this exhibit have been omitted pursuant to a confidential
treatment request. An unredacted version of this exhibit has been filed with the
Commission.
<PAGE>
      10.10 TECHNICAL ASSISTANCE. In addition to other assistance explicitly set
forth in this Agreement, during the period of the Term, Amgen and ViaCell shall
each provide the other Party with reasonable technical assistance relating to
the use of such Amgen Know-How and ViaCell Know-How, respectively, and Joint
Know-How solely to the extent permitted under the license(s) granted to the
other Party in this Agreement. In addition, during the Term each Party shall
make its employees, consultants and agents reasonably available upon reasonable
notice during normal business hours at their respective places of employment to
consult with the other Party on issues relating to any aspect of the subject
matter of this Agreement and in connection with any request from any Regulatory
Authority, including those relating to regulatory, scientific and technical
issues.

      10.11 EMPLOYEE OBLIGATIONS. Prior to beginning work relating to any aspect
of the subject matter of this Agreement and/or being given access to ViaCell
Know-How, Amgen Know-How or Joint Know-How or the Confidential Information of
the other Party, each employee, consultant or agent of ViaCell and Amgen shall
have signed or shall be required to sign a non-disclosure and invention
assignment agreement pursuant to which each such person shall agree to comply
with all of the obligations of ViaCell or Amgen, as appropriate, substantially
including: (a) promptly reporting any invention, discovery, process, software
program or other intellectual property right, as appropriate within ViaCell
Know-How, Amgen Know-How or Joint Know-How; (b) assigning to ViaCell or Amgen,
as appropriate, all of his or her right, title and interest in and to any such
invention, discovery, process, software program or other intellectual property
right; (c) cooperating in the preparation, filing, prosecution, maintenance,
enforcement and defense of any Amgen Patent Rights, ViaCell Patent Rights, Joint
Patent Rights and the enforcement and defense of Amgen Know-How, ViaCell
Know-How and Joint Know-How; (d) performing all acts and signing, executing,
acknowledging and delivering any and all papers, documents and instruments
required for effecting the obligations and purposes of this Agreement and (e)
abiding by the obligations of confidentiality and non-use set forth in this
Agreement. It is understood and agreed that any such non-disclosure and
invention assignment agreement need not be specific to this Agreement.

      10.12 PATENT MARKING. Collaboration Products shall be marked with
appropriate patent numbers or indicia of Patent Rights that cover the
Collaboration Products, to the extent permitted by law in those countries of the
Territory in which such markings have notice value as against infringers of
patents.

      10.13 THIRD PARTY RESEARCH AGREEMENTS. The Parties shall, through the JSC,
agree upon and coordinate Third Party material transfer agreements and
collaboration agreements with academic or governmental research institutions
related to the Development of Collaboration Products or involving the use of
Collaboration Products, in a manner so as to conserve the available quantities
of the Parties' research materials and to avoid compromise of the Parties'
abilities to fulfill their responsibilities under the Program Plan and so as to
maintain access to relevant intellectual property rights. The form of any such
Third Party material transfer agreement or collaboration agreement shall be
agreed upon by the Parties. Notwithstanding the above, other than with respect
to Collaboration Products, neither Party may transfer the other Party's
Materials to any such academic or governmental research institution, without the
express written consent of the other Party.
<PAGE>
      10.14 NO IMPLIED LICENSES. Except as explicitly set forth in their
Agreement, neither Party shall be deemed to have granted, whether by implication
or otherwise, any right or license to the other Party.

                                   ARTICLE 11
                            PAYMENTS; RECORDS; AUDIT

      11.1 PAYMENTS.

            (A) U.S. Dollars. All payments to be made under this Agreement shall
be made in U.S. Dollars by bank wire transfer in immediately available funds to
a bank account designated from time-to-time by the Party receiving the funds.

            (B) Foreign Exchange. Currencies other than United States Dollars
shall be converted into the United States Dollar equivalent at the average rate
of exchange for the Calendar Quarter to which such payments relate (as reported
in Bloomberg Professional, a service of Bloomberg L.P.) or in the event
Bloomberg Professional is not available then The Wall Street Journal, for the
currency of the country in which the sale is made.

            (C) Late Payments. Any amounts not paid by a Party when due under
this Agreement shall be subject to interest from and including the date payment
is due through and including the date upon which such Party has made a wire
transfer of immediately available funds into an account designated by the other
Party of such payment at a rate equal to the lesser of (i) the sum of [**] plus
the [**] of interest quoted in the Money Rates section of the on-line edition of
the Wall Street Journal (at http://www.interactive.wsj.com) calculated daily on
the basis of a 365-day year or (ii) the highest rate permitted by applicable
law.

            (D) Blocked Currency. With respect to receipt of a foreign currency
for sales of Collaboration Products, if the Commercial Lead and its Affiliates
are unable to convert such foreign currency into United States Dollars for
reasons beyond their respective control, or are restricted by law or regulation
from remitting funds from any country of sale, the Commercial Lead shall cause
such payment to be made by deposit to the credit and account of both Parties (or
their respective nominee(s)) in any commercial bank designated by the Commercial
Lead in the applicable country. The Commercial Lead shall deliver to the other
Party proper evidence of such deposit.

      11.2 TAXES.

            (A) Taxes. All excises, taxes, and duties (collectively "Taxes")
levied on account of payments made by Amgen to ViaCell pursuant to this
Agreement will be the responsibility of and paid by ViaCell or subject to the
withholding, remittance, and offset provisions of this Section 11.2.
<PAGE>
            (B) Withholding by Amgen. In the event that Amgen determines that
laws or regulations require withholding of Taxes from any payment to ViaCell
hereunder, such Taxes will be deducted from such payment by Amgen and will be
remitted by Amgen to the appropriate tax authority. Amgen will furnish ViaCell
with proof of payment of such Taxes. In the event that documentation is
necessary in order for ViaCell to secure an exemption from or a reduction in any
withholding of Taxes, ViaCell shall provide such documentation in a timely
manner to Amgen.

            (C) Amgen's Right of Offset. In the event that the governing tax
authority retroactively determines that a payment made to ViaCell pursuant to
this Agreement should have been subject to withholding (or to additional
withholding) for Taxes, Amgen will have the right to offset such amount
(including any interest and penalties that may be imposed thereon) against
future payment obligations of Amgen under this Agreement; provided, however,
that if no further payments or insufficient further payments are available
against which offset may be pursued, Amgen may pursue reimbursement by any
remedy (at law or in equity) available to it. ViaCell have no liability for
interest or penalties imposed as a result solely of Amgen's negligent or willful
failure to withhold Taxes.

      11.3 RECORDS; AUDIT. The Parties shall keep or cause to be kept such
records as are required in sufficient detail to track and determine, in a manner
consistent with GAAP, the accuracy of calculations of all sums or credits due
under this Agreement to accurately account for all Direct Development Costs and
all items within the Operating Profit or Loss account. Such records shall be
retained for a period of the later of: (i) a [**] period following the year in
which any payments were made hereunder, and (ii) the expiration of the
applicable tax statute of limitations (or any extensions thereof), or such
longer period as may be required by law. [**] per [**] each Party shall have the
option to engage, [**], an independent certified public accountant, appointed by
the auditing Party and reasonably acceptable to the audited Party, to examine in
confidence the books and records of the Party being audited as may be necessary
to determine, with respect to any [**], the correctness or completeness of any
report or payment required to be made under this Agreement; provided however,
that the books and records for any particular [**] shall only be subject to one
audit. The report of such accountant shall be limited to a certificate verifying
any report made or payment submitted by the audited Party during such period but
may include, in the event the accountant shall be unable to verify the
correctness of any such payment, information relating to why such payment is
unverifiable. All information contained in any such certificate shall be deemed
the Confidential Information of the audited Party hereunder. If any audit
performed under this Section 11.4 (showing the calculation of a reimbursement or
payment amount) discloses a variance of more than [**] from the amount of the
original report, the audited Party shall bear the full cost of the performance
of such audit. Upon the expiration of [**] following the end of any particular
[**], the calculation of any such amounts payable with respect to such
particular [**] shall be binding and conclusive upon a Party entitled to such
audit and the other Party or its Affiliates shall be released from any liability
or accountability with respect to such amounts for such [**].

[**] Portions of this exhibit have been omitted pursuant to a confidential
treatment request. An unredacted version of this exhibit has been filed with the
Commission.
<PAGE>
                                   ARTICLE 12
                                  PUBLICATIONS

      12.1 PROCEDURE. The JSC shall determine the overall strategy for
publication and presentation of results of pre-clinical and clinical studies of
Cell Therapy Products and Collaboration Products. [**]. Each Party to this
Agreement recognizes that the publication of papers regarding results of and
other information regarding the activities under this Agreement, including oral
presentations and abstracts, may be beneficial to both Parties provided such
publications are subject to reasonable controls to protect Confidential
Information and other interests of the Parties. In particular, it is the intent
of the Parties to maintain the confidentiality of any Confidential Information
included in any patent application until such patent application has been
published. Accordingly, each Party will have the right to review and approve any
paper proposed for publication by the other Party, including oral presentations
and abstracts, which utilizes data generated under this Agreement and/or
includes Confidential Information of the other Party. Before any such paper is
submitted for publication or an oral presentation is made, the Party publishing
or presenting will deliver a complete copy of the paper or materials and
abstracts for oral presentation to the other Party at least [**] prior to
submitting the paper to a publisher or making the presentation. The other Party
will review any such paper and give its comments to the publishing Party within
[**] after the delivery of such paper to the other Party. With respect to oral
presentation materials and abstracts, the other Party will make reasonable
efforts to expedite review of such materials and abstracts, and will return such
items as soon as practicable to the presenting Party with appropriate comments,
if any, but in no event later than [**] after the date of delivery to the other
Party. The publishing Party will comply with the other Party's request to delete
references to the other Party's Confidential Information in any such paper,
materials and abstracts and agrees to withhold publication of same for an
additional [**] in order to permit the Parties to obtain patent protection, if
either of the Parties deems it necessary, in accordance with the terms of this
Agreement.

      12.2 CREDIT. Any such publication or presentation will include recognition
of the contributions of the other Party according to standard practice for
assigning scientific credit, either through authorship or acknowledgment, as may
be appropriate.

[**] Portions of this exhibit have been omitted pursuant to a confidential
treatment request. An unredacted version of this exhibit has been filed with the
Commission.
<PAGE>
                                   ARTICLE 13
                                 CONFIDENTIALITY

      13.1 TREATMENT OF CONFIDENTIAL INFORMATION. The Parties agree that during
the Term, and continuing until [**] after this Agreement expires or terminates
and for Confidential Information that constitutes trade secrets, as defined
under the laws of the State of California, for so long as such Confidential
Information actually constitutes trade secrets, a Party receiving Confidential
Information of the other Party shall (a) maintain in confidence such
Confidential Information to the same extent such Party maintains its own
confidential or proprietary information or trade secrets of similar kind and
value (but at a minimum each Party shall use reasonable best efforts to maintain
such Confidential Information in confidence); (b) not disclose such Confidential
Information to any Third Party without the prior written consent of the
disclosing Party, except for (i) disclosures to its Affiliates and, pursuant to
Section 18.5, authorized subcontractors who (in the case of both Affiliates and
subcontractors) agree to be bound by obligations of non-disclosure and non-use
at least as stringent as those contained in this Article 13 and (ii) disclosures
to Third Parties as permitted by Section 13.4 hereof; and (c) not use such
Confidential Information for any purpose except those purposes permitted by this
Agreement. Neither Party shall knowingly disclose to the other Party any Third
Party information or know-how that such Party does not have the legal right to
disclose to the other Party and/or has a contractual obligation not to disclose
to the other Party.

      13.2 AUTHORIZED DISCLOSURE. Notwithstanding any other provision of this
Agreement, a Party may disclose Confidential Information of the other Party:

            (A) to the extent and to the persons and entities as required by an
applicable law, rule, regulation, legal process, court order or the rules of the
National Association of Securities Dealers or of a Regulatory Authority;

            (B) as necessary to file, prosecute or defend those patent
applications or patents for which either Party has the right to assume filing,
prosecution, defense or maintenance, pursuant to Article 10 of this Agreement;

            (C) to prosecute or defend litigation or otherwise establish rights
or enforce obligations pursuant to this Agreement, but only to the extent that
any such disclosure is necessary; or

            (D) in the event of a Recall, by the Party responsible for such
Recall pursuant to Section 5.9.

The Party required or intending to disclose the other Party's Confidential
Information under Sections 13.2(a) or (c) shall first have given prompt notice
to such other Party to enable it to seek any available exemptions from or
limitations on such disclosure requirement and shall reasonably cooperate in
such efforts by the other Party.

Additionally, notwithstanding anything herein or any other express or implied
agreement, arrangement or understanding to the contrary, the Parties acknowledge
and agree that (i) any obligations of confidentiality contained herein and
therein do not apply and have not applied from the commencement of discussions
between the Parties to the tax treatment and tax structure

[**] Portions of this exhibit have been omitted pursuant to a confidential
treatment request. An unredacted version of this exhibit has been filed with the
Commission.
<PAGE>
of the transactions contemplated by this Agreement (and any related transactions
or agreements) and (ii) each Party to this Agreement (and each of its employees,
representatives or other agents) may disclose to any and all persons, without
limitation of any kind, the tax treatment and tax structure of the transactions
contemplated by this Agreement and all materials of any kind (including opinions
or other tax analyses) that are provided to it relating to such tax treatment
and tax structure. This authorization to disclose the tax treatment and tax
structure is limited to the extent that confidentiality is required to comply
with any applicable securities laws. This authorization is not intended to
permit disclosure of any other information including, without limitation, (i)
any portion of any materials to the extent not related to the transaction's tax
treatment or tax structure, (ii) the identities of participants or potential
participants, (iii) the existence or status of any negotiations, (iv) any
pricing or financial information (except to the extent such pricing or financial
information is related to the transaction's tax treatment or tax structure), or
(v) any other term or detail not relevant to the transaction's tax treatment or
tax structure.

      13.3 TRANSFER OF MATERIALS. For purposes of this Agreement, the Parties
anticipate that each Party may transfer certain of its Materials to the other
Party. Each Party agrees that it will use such Materials of the other Party only
in accordance with the terms and conditions of this Agreement and will not
transfer such Materials to any Third Party without the consent of the other
Party, except as expressly permitted under this Agreement.

      13.4 PUBLICITY; TERMS OF AGREEMENT. The Parties agree that the material
terms of this Agreement shall be considered Confidential Information of both
Parties, subject to the special authorized disclosure provisions set forth below
in this Section 13.4 (in lieu of the authorized disclosure provisions set forth
in Section 13.2, to the extent of any conflict) and without limiting the
generality of the definition of Confidential Information. The Parties will
mutually agree on the text of a press release announcing the execution of this
Agreement. Thereafter, if either Party desires to make a public announcement
concerning this Agreement or the terms hereof, such Party shall give reasonable
prior advance notice of the proposed text of such announcement to the other
Party for its prior review and approval, such approval not to be unreasonably
withheld. A Party shall not be required to seek the permission of the other
Party to repeat any information as to the terms of this Agreement that has
already been publicly disclosed by such Party in accordance with the foregoing
or by the other Party. Either Party may disclose the terms of this Agreement (i)
as required by law, and (ii) to bona fide potential material investors or
acquirors and Representatives of such investors or acquirors who (in the case of
potential investors and acquirors and their Representatives) agree to be bound
by obligations of non-disclosure and non-use at least as stringent as those
contained in this Article 13. ViaCell may disclose the terms of the Agreement to
the parties to that certain Third Amended and Restated Investors' Rights
Agreement, dated as of September 30, 2003, among ViaCell and the investors
listed therein to obtain such parties consent thereunder. The Parties
acknowledge that Amgen and/or ViaCell may be obligated to file a copy of this
Agreement with the U.S. Securities and Exchange Commission, and each such Party
shall be entitled to make such filing, provided however, that it requests
confidential treatment of the more sensitive terms hereof to the extent such
confidential treatment is reasonably available to the filing Party under the
circumstances then prevailing. In the event of any such filing, the filing Party
will provide the non-filing Party with an advance copy of the Agreement marked
to show provisions for which the filing Party intends to seek

[**] Portions of this exhibit have been omitted pursuant to a confidential
treatment request. An unredacted version of this exhibit has been filed with the
Commission.
<PAGE>
confidential treatment, and the filing Party shall reasonably consider the
non-filing Party's timely comments thereon.

                                   ARTICLE 14
                    REPRESENTATIONS, WARRANTIES AND COVENANTS

      14.1 MUTUAL REPRESENTATIONS AND WARRANTIES. Each Party hereby represents
and warrants to the other Party that as of the Effective Date:

            (A) Power and Authority. It has the corporate power, authority and
legal right to enter into this Agreement and perform its obligations hereunder
and has taken all necessary corporate action on its part required to authorize
the execution and delivery of the Agreement and the performance of its
obligations hereunder, including without limitation the right to grant the
licenses hereunder.

            (B) Binding Agreement. This Agreement has been duly executed and
delivered on behalf of ViaCell and constitutes a legal, valid and binding
obligation of ViaCell that is enforceable against it in accordance with its
terms.

            (C) No Conflict. The execution, delivery and performance of this
Agreement does not conflict with, and would not result in a breach of any
agreement, instrument or understanding, oral or written, to which it is a party
or by which it may be bound, nor violate any material law or regulation of any
court, governmental body or administrative or other agency having jurisdiction
over it.

            (D) Validity. It is aware of no action, suit, inquiry or
investigation instituted by any Third Party which questions or threatens the
validity of this Agreement.

            (E) Business Condition. It is not in violation of its charter,
bylaws, or any other organizational document, or in violation of any law,
administrative regulation, ordinance or order of any court or governmental
agency, arbitration panel or authority applicable to it, which violation,
individually or in the aggregate, would reasonably likely have a materially
adverse effect on its business or financial condition. Except as may be set
forth in any documents filed with the Securities and Exchange Commission, as
required to be filed by it under the Securities Act or Exchange Act, as the case
may be, or in the Securities Purchase Agreement entered into concurrently by the
Parties, it is not aware of any facts or circumstances, individually or in the
aggregate, which would reasonably likely have a materially adverse effect on its
business or financial condition.

      14.2 MUTUAL COVENANTS. Each Party hereby covenants to the other Party as
follows:

            (A) No Misappropriation. It shall not knowingly misappropriate the
trade secret of a Third Party in its activities to Develop, manufacture or
Commercialize Collaboration Products.

            (B) No Debarment. In the course of the Development, manufacture and
Commercialization of Collaboration Products and during the Term, such Party
shall not knowingly use and shall not have knowingly used any employee or
consultant who is or has been

[**] Portions of this exhibit have been omitted pursuant to a confidential
treatment request. An unredacted version of this exhibit has been filed with the
Commission.
<PAGE>
debarred by a Regulatory Authority or, to the best of such Party's knowledge, is
or has been the subject of debarment proceedings by a Regulatory Authority.

            (C) No Conflict. It shall not during the term of this Agreement
grant any right, license, consent or privilege to any Third Party(ies) in the
Territory which would conflict with the rights granted to the other Party under
this Agreement, and shall not take any action that would in any way prevent it
from assuming its obligations or granting the rights granted to the other Party
under this Agreement or that would otherwise materially conflict with or
adversely affect its obligations or its assumption of the rights granted to the
other Party under this Agreement.

            (D) Compliance. Each Party shall comply with all applicable
statutes, regulations and guidance of Regulatory Authorities in carrying out its
respective activities regarding the Development, manufacture and
Commercialization of Collaboration Products in the Territory.

            (E) Regulatory Data. It shall store and provide the other Party
access to source data supporting all Regulatory Filings and Regulatory Approvals
for the longer of (i) [**] or (ii) the time period required by any applicable
Regulatory Authority in the Territory.

            (F) Formation of Legal Entity. In the event either Party establishes
that the formation of a partnership or other legal entity for which no
entity-level tax is imposed, co-owned by the Parties to further the Development,
manufacture and Commercialization of the Collaboration Products would be
beneficial for legal, tax or other reasons, and would not cause the other Party
any significant financial detriment, the other Party covenants that it shall
cooperate and take all reasonable steps necessary to form such entity.

      14.3 ADDITIONAL REPRESENTATIONS, WARRANTIES AND COVENANTS OF VIACELL.

            (A) Corporate Existence. ViaCell hereby represents and warrants to
Amgen that as of the Effective Date of this Agreement it is a corporation duly
organized, validly existing and in good standing under the laws of the State of
Delaware, and has full corporate power and authority and the legal right to own
and operate its property and assets and to carry on its business as it is now
being conducted and as contemplated in this Agreement.

[**] Portions of this exhibit have been omitted pursuant to a confidential
treatment request. An unredacted version of this exhibit has been filed with the
Commission.
<PAGE>
            (B) Diligence. ViaCell covenants that it shall use Commercially
Reasonable Efforts to carry out its obligations in accordance with the terms of
this Agreement including, as applicable, the Development and manufacture of Cell
Therapy Products and the manufacture of Collaboration Products in the Territory
in accordance with the terms of this Agreement. Without limiting the generality
of the foregoing obligation, ViaCell covenants that ViaCell shall use
Commercially Reasonable Efforts to administer a Cell Therapy Product to a
patient in a government-approved clinical trial [**] after the Effective Date.

            (C) Exclusivity. ViaCell shall work exclusively with Amgen with
respect to Cell Therapy Products and Collaboration Products.

      14.4 ADDITIONAL REPRESENTATIONS, WARRANTIES AND COVENANTS OF AMGEN.

            (A) Corporate Existence. Amgen hereby represents and warrants to
ViaCell that as of the Effective Date of this Agreement it is a corporation duly
organized, validly existing and in good standing under the laws of the State of
Delaware, and has full corporate power and authority and the legal right to own
and operate its property and assets and to carry on its business as it is now
being conducted and as contemplated in this Agreement.

            (B) Diligence. Amgen covenants that it shall use Commercially
Reasonable Efforts to carry out its obligations under the terms of this
Agreement including, as applicable, the Development, manufacture and
Commercialization of Collaboration Products in the Territory in accordance with
the terms of this Agreement.

      14.5 DISCLAIMERS. EXCEPT AS EXPRESSLY PROVIDED HEREIN, THE MATERIALS,
CONTRIBUTED PRODUCTS AND INFORMATION PROVIDED HEREUNDER ARE BEING PROVIDED "AS
IS" AND WITHOUT ANY REPRESENTATIONS OR WARRANTIES. EXCEPT AS EXPRESSLY PROVIDED
HEREIN, NEITHER PARTY MAKES ANY REPRESENTATIONS OR WARRANTIES, EXPRESS OR
IMPLIED, OF ANY TYPE WHATSOEVER. EACH PARTY EXPRESSLY DISCLAIMS ANY WARRANTY OF
MERCHANTABILITY, OF FITNESS FOR A PARTICULAR PURPOSE OR OF NONINFRINGEMENT.

[**] Portions of this exhibit have been omitted pursuant to a confidential
treatment request. An unredacted version of this exhibit has been filed with the
Commission.
<PAGE>
                                   ARTICLE 15
                                 INDEMNIFICATION

      15.1 INDEMNIFICATION BY AMGEN. Amgen hereby agrees to defend, hold
harmless and indemnify (collectively "Indemnify" or "Indemnified") ViaCell and
its Affiliates, agents, directors, officers and employees (the "ViaCell
Indemnitees") from and against any and all Losses resulting directly or
indirectly from any Third Party claims, suits, actions or demands, whether
brought during or after the Term, arising out of (a) any of Amgen's
representations and warranties set forth in this Agreement being untrue in any
material respect when made; (b) any material breach or material default by Amgen
of its covenants and obligations under this Agreement; or (c) Amgen's carrying
out of activities outside the Program Plan during the Term or Amgen's negligence
or intentional misconduct (or the negligence or intentional misconduct of any
Third Party engaged by Amgen). To be eligible to be so Indemnified as described
in this Section 15.1, the ViaCell Indemnitees shall provide Amgen with prompt
notice of any claims, suits, actions or demands (with a description of the claim
and the nature and amount of any such Loss) giving rise to the indemnification
obligation pursuant to this Section 15.1 and the exclusive ability to defend
such claims, suits, actions or demands (with the reasonable cooperation of
ViaCell Indemnitees). ViaCell shall have the right to retain its own counsel, at
its own expense, if representation of the counsel of Amgen would be
inappropriate due to actual or potential differing interests between the
Parties. Neither Party shall settle or consent to the entry of any judgment with
respect to any claim for Loss for which indemnification is sought, without the
prior written consent of the other Party (not to be unreasonably withheld).
Amgen's obligation to Indemnify the ViaCell Indemnitees pursuant to this Section
15.1 shall not apply to the extent of any Losses (i) that arise from the
negligence or intentional misconduct of any ViaCell Indemnitee (including but
not limited to that arising from the Development or Commercialization of a
Collaboration Product by ViaCell); (ii) that arise from ViaCell's breach of any
representation, warranty, covenant or obligation under this Agreement; or (iii)
for which ViaCell is obligated to Indemnify the Amgen Indemnitees pursuant to
Section 15.2 of this Agreement.

      15.2 INDEMNIFICATION BY VIACELL. ViaCell hereby agrees to Indemnify Amgen
and its Affiliates, agents, directors, officers and employees (the "Amgen
Indemnitees") from and against any and all Losses resulting directly or
indirectly from any Third Party claims, suits, actions or demands, whether
brought during or after the Term, arising out of (a) any of ViaCell's
representations and warranties set forth in this Agreement being untrue in any
material respect when made; (b) any material breach or material default by
ViaCell of its covenants and obligations under this Agreement; (c) ViaCell's
carrying out of activities outside the Program Plan during the Term or ViaCell's
negligence or intentional misconduct (or the negligence or intentional
misconduct of any Third Party engaged by ViaCell) in carrying out its activities
set forth in the Program Plan including, without limitation, Development
activities of ViaCell; and/or (d) resulting from the use or sale of any Cell
Therapy Product or Unoptioned Cell Therapy Product. To be eligible to be
Indemnified as described above in this Section 15.2, the Amgen Indemnitees shall
provide ViaCell with prompt notice of any claims, suits, actions or demands
(with a description of the claim and the nature and amount of any such Loss)
giving rise to the indemnification obligation pursuant to this Section 15.2 and
the exclusive ability to defend such claims, suits, actions or demands (with the
reasonable cooperation of Amgen Indemnitees). Amgen shall have the right to
retain its own counsel, at its own expense, if representation of the counsel of
ViaCell would be inappropriate

[**] Portions of this exhibit have been omitted pursuant to a confidential
treatment request. An unredacted version of this exhibit has been filed with the
Commission.
<PAGE>
due to actual or potential differing interests between the Parties. Neither
Party shall settle or consent to the entry of any judgment with respect to any
claim for Loss for which indemnification is sought, without the prior written
consent of the other Party (not to be unreasonably withheld). ViaCell's
obligation to Indemnify the Amgen Indemnitees pursuant to this Section 15.2
shall not apply to the extent of any Losses (i) that arise from the negligence
or intentional misconduct of any Amgen Indemnitee (including but not limited to
that arising from the manufacture or Commercialization of a Collaboration
Product by Amgen); (ii) that arise from Amgen's breach of any representation,
warranty, covenant or obligation under this Agreement; or (iii) for which Amgen
is obligated to Indemnify the ViaCell Indemnitees pursuant to Section 15.1 of
this Agreement.

      15.3 JOINT LIABILITY. Other than as set forth in Section 15.1 or 15.2 and
after exhausting the minimum insurance coverage as listed in the table in
Section 15.4, any and all Losses arising from Third Party claims, suits, actions
or demands, whether brought during or after the Term, resulting directly or
indirectly out of the making, having made, using, selling, having sold, offering
for sale or resale, and/or otherwise Developing, manufacturing, or
Commercializing Collaboration Products (including a claim that a Collaboration
Product caused death or personal injury of any kind) during the Term shall be
charged to the Operating Profit or Loss account. In the event a Party becomes
aware of a claim which, if resulting in a Loss, it intends to charge to the
Operating Profit or Loss account, such Party shall inform the other Party of
such claim as soon as reasonably practicable after it receives notice thereof.
Subject to Section 10.7, ViaCell shall have the right to assume direction and
control of the defense of any claim relating to a Collaboration Product alleging
a date of injury (or in the event of a continuing injury alleging the then-most
recent date of injury) to be prior to the Transition Date for that Collaboration
Product, and Amgen shall have the right to assume direction and control of the
defense of any claim relating to a Collaboration Product alleging a date of
injury (or in the event of a continuing injury alleging the then-most recent
date of injury) to be upon or after the Transition Date for that Collaboration
Product. The Party not in control of such defense shall cooperate as requested
in the defense of the claim and if the Party in control of such defense finds it
necessary or desirable to join the other Party as a party, the other Party shall
execute all papers or perform such other acts as may reasonably be required by
the Party in control of such defense; provided however, that the other Party
shall have the right to retain its own counsel, at its own expense, if
representation by the counsel of the Party in control would be inappropriate due
to actual or potential differing interests between the Parties. Neither Party
shall settle or consent to the entry of any judgment with respect to any claim
for Losses associated with such claim, without the other Party's prior written
consent.

      15.4 INSURANCE. Within [**] after the Effective Date, each Party shall at
its own expense procure and maintain during the Term and for a period of [**]
thereafter an insurance policy/policies, including product liability insurance
(but excluding clinical trial insurance policies which shall be required only
while trials are ongoing), adequate to cover its obligations hereunder and which
is/are consistent with normal business practices of prudent companies similarly
situated. Amgen may self-insure all or part of any such obligation consistent
with pharmaceutical industry practices but ViaCell shall at all times maintain
the following minimum Third Party insurance coverage, provided that ViaCell need
not maintain clinical trial liability insurance prior to commencing its first
clinical trial:

[**] Portions of this exhibit have been omitted pursuant to a confidential
treatment request. An unredacted version of this exhibit has been filed with the
Commission.
<PAGE>
<TABLE>
<CAPTION>
                            Type of Coverage                    Amount
                            ----------------                    ------
<S>                                                             <C>
            Commercial General Liability Insurance               $[**]
                                                                 $[**]

            Product Liability Insurance                          $[**]
                                                                 $[**]

            Clinical Trial Liability Insurance                   $[**]

            Workman's Compensation                                [**]
</TABLE>

Each insurance policy required by and procured by a Party under this Section
15.4 shall name the other Party as an additional insured. Such insurance shall
not be construed to create a limit of the insuring Party's liability with
respect to its indemnification obligations under this Article 15. Each Party
shall provide the other Party with a certificate of insurance or other evidence
of such insurance and/or self-insurance, upon request. Each Party shall provide
the other Party with written notice at least [**] prior to the cancellation,
non-renewal or a material change in such insurance or self-insurance which
materially adversely affects the rights of the other Party hereunder.

      15.5 LIMITATION OF LIABILITY. NEITHER PARTY NOR ITS RESPECTIVE AFFILIATES
SHALL BE LIABLE FOR SPECIAL, EXEMPLARY, CONSEQUENTIAL OR PUNITIVE DAMAGES,
WHETHER IN CONTRACT, WARRANTY, TORT, STRICT LIABILITY OR OTHERWISE INCURRED BY
THE OTHER PARTY IN CONNECTION WITH THIS AGREEMENT, INCLUDING BUT NOT LIMITED TO
DAMAGES MEASURING LOST PROFITS OR BUSINESS OPPORTUNITIES.

                                   ARTICLE 16
                              TERM AND TERMINATION

      16.1 TERM. This Agreement shall become effective on the Effective Date and
shall remain in full force and effect, unless earlier terminated pursuant to
this Article 16, until the later of: (a) the expiration of the Amgen Patent
Rights or (b) the date on which there are no Collaboration Products being
Developed or Commercialized by the Parties.

      16.2 TERMINATION FOR DILIGENCE FAILURE. In the event ViaCell is in an
uncured material breach of its diligence obligations set forth in the second
sentence of Section 14.3(b), Amgen shall have the right, in its sole discretion,
to terminate this Agreement by providing [**] prior written notification of
termination to ViaCell.

[**] Portions of this exhibit have been omitted pursuant to a confidential
treatment request. An unredacted version of this exhibit has been filed with the
Commission.
<PAGE>
      16.3 MUTUAL CONSENT. This Agreement shall terminate upon the mutual
written consent of the Parties and, unless otherwise specified in such written
consent, shall be effective [**] after the date of last signature of the Parties
to such mutual written consent.

      16.4 TERMINATION FOR DEFAULT.

            (A) In the event any material representation or warranty made
hereunder by either Party shall have been untrue in any material respect
("Representation Default"), or upon any material breach or material default of a
material obligation of this Agreement by a Party ("Performance Default"), the
Party not in default ("Non-Defaulting Party") must first give the other Party
("Defaulting Party") written notice thereof ("Notice of Default"), which notice
must state the nature of the Representation Default or Performance Default in
reasonable detail and must request the Defaulting Party cure such Representation
Default or Performance Default within [**]. During any such [**] period after
receipt or delivery of a Notice of Default under this Section 16.4(a) for which
termination of this Agreement, in whole or in part, is a remedy, all of the
Parties' respective rights and obligations under the affected parts of this
Agreement, including but not limited to Development, manufacture and
Commercialization, shall (to the extent applicable) remain in force and effect.
If the Defaulting Party shall dispute the existence, extent or nature of any
default set forth in a Notice of Default, the Parties shall use good faith
efforts to resolve the dispute.

            (B) ViaCell Default. In the event of a Representation Default or a
Performance Default by ViaCell that shall not have been cured within the period
set forth in Section 16.4(a) above after receipt of a Notice of Default, Amgen,
at its option, may terminate this Agreement upon [**] prior written notice. The
effects of such termination will occur in accordance with Section 16.6(a).

            (C) Amgen Default. In the event of a Representation Default or a
Performance Default by Amgen that shall not have been cured within the period
set forth in Section 16.4(a) after receipt of a Notice of Default, ViaCell, at
its option, may terminate this Agreement upon [**] prior written notice. The
effects of such termination will occur in accordance with Section 16.6(b).

            (D) Excluded Events. For the avoidance of doubt, in the event that
ViaCell fails to exercise Commercially Reasonable Efforts in relation to its
obligations to manufacture Collaboration Products, then such failure to exercise
Commercially Reasonable Efforts shall be deemed to not constitute a Performance
Default.

[**] Portions of this exhibit have been omitted pursuant to a confidential
treatment request. An unredacted version of this exhibit has been filed with the
Commission.
<PAGE>
      16.5 BANKRUPTCY.

            (A) Amgen may terminate the Agreement if ViaCell shall file in any
court or agency pursuant to any statute or regulation of any state or country, a
petition in bankruptcy or insolvency or for reorganization or for an arrangement
or for the appointment of a receiver or trustee of ViaCell or of its assets, or
if ViaCell proposes a written agreement of composition or extension of its
debts, or if ViaCell shall be served with an involuntary petition in bankruptcy
or seeking reorganization, liquidation, dissolution, winding-up arrangement,
composition or readjustment of its debts or any other relief under any
bankruptcy, insolvency, reorganization or other similar act or law of any
jurisdiction now or hereafter in effect, or there shall have been issued a
warrant of attachment, execution, distraint or similar process against it, filed
in any insolvency proceeding, and such petition shall not be dismissed within
[**] after the filing thereof, or if ViaCell shall propose or be a party to any
dissolution or liquidation, or if ViaCell shall make an assignment for the
benefit of creditors. The effects of such termination will occur in accordance
with Section 16.6(a).

            (B) All rights and licenses granted under or pursuant to this
Agreement by Amgen or ViaCell are, and shall otherwise be deemed to be, for
purposes of Section 365(n) of the U.S. Bankruptcy Code, licenses of rights to
"intellectual property" as defined under Section 101 of the U.S. Bankruptcy
Code. The Parties agree that each Party shall retain and may fully exercise all
of its rights and elections under the U.S. Bankruptcy Code. The Parties further
agree that, in the event of the commencement of a bankruptcy proceeding by or
against a bankrupt Party under the U.S. Bankruptcy Code, the other Party shall
be entitled to a complete duplicate of (or complete access to, as appropriate)
any intellectual property and all embodiments of such intellectual property, and
same, if not already in the other Party's possession, shall be promptly
delivered to the other Party (a) upon any such commencement of a bankruptcy
proceeding, upon the other Party's written request therefor, unless the
non-bankrupt Party (or a trustee on behalf of the non-bankrupt Party) elects to
continue to perform all of its obligations under this Agreement or (b) if not
delivered under (a) above, upon the rejection of this Agreement by or on behalf
of the non-bankrupt Party, upon written request therefor by the other Party.

      16.6 EFFECTS OF TERMINATION. In addition to any other remedies which may
be available at law or equity, upon termination of this Agreement the rights and
obligations of the Parties relating to confidentiality shall survive as provided
in Article 13 and indemnification shall survive for a period of three years and
the other rights and obligations of the Parties shall be as set forth in this
Section 16.6.

            (A) Upon termination of this Agreement by Amgen in accordance with
either Sections 16.2, 16.4(b) or 16.5, Amgen shall retain all rights granted to
it under this Agreement, but all of its obligations, [**], shall immediately
terminate. Upon such termination, ViaCell shall also grant to Amgen full and
complete rights to manufacture the Collaboration Products and shall provide all
necessary Materials, Information and assistance (at Amgen's expense) as Amgen
may reasonably request to facilitate Amgen commencing such manufacture of the
Collaboration Products.

[**] Portions of this exhibit have been omitted pursuant to a confidential
treatment request. An unredacted version of this exhibit has been filed with the
Commission.
<PAGE>
            (B) Upon termination of this Agreement by ViaCell in accordance with
Section 16.4(c), ViaCell shall retain all rights granted to it under this
Agreement, but all of its obligations shall immediately terminate, except, to
the extent that the first Transition Date has already passed, [**] between the
parties shall survive. Upon such termination, Amgen shall also grant to ViaCell
full and complete right to Develop and Commercialize the Collaboration Products
and shall provide all necessary Materials, Information and assistance (at
ViaCell's expense) as ViaCell may reasonably request to facilitate ViaCell
commencing Development and Commercialization of the Collaboration Products,
subject to the provisions of Section 7.3 above.

            (C) Upon termination of this Agreement for any other reason, each
party's rights and obligations hereunder shall immediately terminate, except for
those relating to confidentiality and indemnification, as described above.

      16.7 TRANSITION. After a notice of termination has been delivered pursuant
to any one of Sections 16.2 to 16.5, each Party shall, in no event in excess of
[**] after the delivery date of such notice (other than with respect to
obligations which explicitly exceed such [**] period), assist (and be
responsible for its own costs and expenses) in the transition of affairs as set
forth in this Article 16 in a timely, reasonable and businesslike manner. Such
assistance shall include, but not be limited to (i) making its personnel and
other resources reasonably available to the other Party, as necessary and (ii)
transferring copies of all relevant information, files or data containing
Information and all Materials to the non-terminating Party. Thereafter, unless
explicitly set forth in Sections 16.2 through 16.6, as appropriate, the Parties
shall have no further obligation to assist in such transition.

      16.8 ACCRUED RIGHTS. Termination, relinquishment or expiration of any
licenses under this Agreement or of this Agreement for any reason in accordance
with this Article 16 shall be without prejudice to any rights which shall have
accrued to the benefit of either Party or any liability incurred by either Party
prior to the effective date of such termination, relinquishment or expiration
and shall not preclude either Party from pursuing all rights and remedies it may
have hereunder or at law or in equity with respect to any breach of this
Agreement nor prejudice either Party's right to obtain performance of any
obligation.

[**] Portions of this exhibit have been omitted pursuant to a confidential
treatment request. An unredacted version of this exhibit has been filed with the
Commission.
<PAGE>
                                   ARTICLE 17
                               DISPUTE RESOLUTION

      17.1 DISPUTES. The Parties recognize that disputes as to certain matters
may from time to time arise during the term of this Agreement which relate to
either Party's rights and/or obligations hereunder and which are not resolved by
the JSC. It is the objective of the Parties to establish procedures to
facilitate the resolution of disputes arising from, concerning or in any way
relating to this Agreement in an expedient manner by mutual cooperation and
without resort to litigation. To accomplish this objective, the Parties agree to
follow the procedures set forth in this Section 17.1 if and when such a dispute
arises under this Agreement (other than with respect to disputes to be resolved
in accordance with Section 2.5(b)(i)-(iv) or, as set forth in this Agreement,
disputes explicitly excluded from being resolved pursuant to this Article 17).
The Parties shall undertake good faith efforts to resolve any such dispute in
good faith. In the event the Parties shall be unable to resolve such dispute,
either Party may, by written notice to the other Party, have any dispute between
the Parties referred to their respective executive officers designated below (or
their designees or successors), for attempted resolution by good faith
negotiations within [**] after such notice is received. Such designated officers
are as follows:

                     For ViaCell:       ViaCell's General Counsel

                     For Amgen:         Amgen's General Counsel

If the designated officers are not able to resolve such dispute within such
fifteen (15) day period, the dispute will be referred to the respective Chief
Executive Officers of each Party, or their Senior Vice President designee(s). If
the Chief Executive Officers (or their designees) are unable to resolve such
dispute within such further 15-day period, either Party may at any time
thereafter pursue any legal or equitable remedy available to it. Notwithstanding
the above, either Party shall be entitled at all times and without delay to seek
equitable relief.

      17.2 GOVERNING LAW; JUDICIAL RESOLUTION. Resolution of all disputes
arising out of or related to this Agreement or the performance, enforcement,
breach or termination of this Agreement and any remedies relating thereto, shall
be governed by and construed under the substantive laws of the State of New
York, as applied to agreements executed and performed entirely in the State of
New York by residents of the State of New York, without regard to conflicts of
law rules. Any dispute arising under this Agreement shall be submitted to a
state or federal court of competent jurisdiction in the State of New York.

[**] Portions of this exhibit have been omitted pursuant to a confidential
treatment request. An unredacted version of this exhibit has been filed with the
Commission.
<PAGE>
                                   ARTICLE 18
                                     GENERAL

      18.1 FORCE MAJEURE. Both Parties shall be excused from the performance of
their obligations under this Agreement to the extent that such performance is
prevented by Force Majeure and the nonperforming Party promptly provides notice
of the prevention to the other Party. Such excuse shall be continued so long as
the condition constituting Force Majeure continues and the nonperforming Party
uses reasonable efforts to remove the condition. When such circumstances arise,
the Parties shall discuss what, if any, modification of the terms of this
Agreement may be required in order to arrive at an equitable solution.

      18.2 NOTICES. Any notice required or permitted to be given under this
Agreement shall be in writing, shall specifically refer to this Agreement and
shall be deemed to have been sufficiently given for all purposes if mailed by
first class certified or registered mail, postage prepaid, express delivery
service or personally delivered, or if sent by facsimile, electronic
transmission confirmed. Unless otherwise notified in writing, the mailing
addresses and fax numbers for notice of the Parties shall be as described below.

                     For ViaCell:    ViaCell, Inc.
                                     131 Clarendon Street, 3rd Floor
                                     Boston, Massachusetts  02116
                                     Attn:  President
                                     Facsimile: (617) 266-9391

                                     With a copy to:

                                     Goodwin Procter LLP
                                     Exchange Place
                                     Boston, Massachusetts  02109
                                     Attn:  Laura C. Hodges Taylor, Esq.
                                     Facsimile:  (617) 523-1231

                     For Amgen:      Amgen Inc.
                                     One Amgen Center Drive
                                     Thousand Oaks, California 91320-1799
                                     Facsimile: (805) 499-6058
                                     Attention:  Vice President, Licensing

                                     With a copy to:  Corporate Secretary
                                     Facsimile: (805) 499-8011

      18.3 MAINTENANCE OF RECORDS. Each Party shall keep and maintain all
records required by law or regulation with respect to Collaboration Products and
shall make copies of such records available to the other Party upon request.

      18.4 NO STRICT CONSTRUCTION. This Agreement has been prepared jointly and
shall not be strictly construed against either Party.

[**] Portions of this exhibit have been omitted pursuant to a confidential
treatment request. An unredacted version of this exhibit has been filed with the
Commission.
<PAGE>
      18.5 PERFORMANCE BY AFFILIATES. Each of Amgen and ViaCell acknowledge that
obligations under this Agreement may be performed by Affiliates of Amgen and
ViaCell and that each of Amgen and ViaCell may grant its respective Affiliates a
license or sublicense to (or covenant not to sue under) Amgen Technology,
ViaCell Technology, Joint Know-How, Joint Patent Rights, Amgen Trademarks,
ViaCell Trademarks and Product Trademarks, as applicable, only to the extent and
only for so long as such license or sublicense or covenant not to sue is
necessary for such Affiliate to perform such tasks. Each of Amgen and ViaCell
guarantees performance of this Agreement by its Affiliates, notwithstanding any
assignment to Affiliates in accordance with Section 18.7 below. Wherever in this
Agreement the Parties delegate responsibility to Affiliates or local operating
entities, the Parties agree that such entities may neither make decisions
inconsistent with this Agreement, amend the terms of this Agreement nor act
contrary to its terms in any way. The Party granting a license or sublicense to
its Affiliates shall forward to the other Party a copy of each fully executed
license or sublicense agreement, within [**] of the execution of each such
license or sublicense agreement.

      18.6 SUBCONTRACTING. The Parties acknowledge and agree that the following
portions of the work involved in Development, manufacture and Commercialization
of Collaboration Products may be subcontracted to a Third Party by the
responsible Party: (i) the Development Lead may contract with/establish clinical
sites, investigators and CROs pursuant to Article 3; (ii) the Parties may
subcontract to a Third Party manufacturer pursuant to Article 7; and (iii) the
Commercialization Lead may decide to enter into agreements with distributors or
sublicensees for commercial distribution of Collaboration Products; (provided
however, [**]). The Party entering into such subcontract may as part of such
subcontract grant to such Third Party a license or sublicense to Amgen
Technology, ViaCell Technology, Joint Know-How, Joint Patent Rights, Amgen
Trademarks, ViaCell Trademarks and Product Trademarks, as applicable, only to
the extent and only for so long as such license or sublicense is necessary for
such Third Party to perform such tasks and subject to the provisions of Sections
10.2 and 10.3; provided however, that the responsible Party remains responsible
for the satisfactory accomplishment of such work in accordance with the terms
and conditions of this Agreement and that the subcontractor shall enter into a
written agreement binding such subcontractor to the obligations the responsible
Party has to the other Party (and containing any other provisions normal and
customary for similar types of agreements). The subcontracting Party shall
forward to the other Party a copy of each fully executed subcontracting
agreement, within [**] of the execution of each such agreement.
<PAGE>
      18.7 ASSIGNMENT. Neither Party shall assign or transfer this Agreement or
any rights or obligations hereunder without the prior written consent of the
other Party, except that each Party is expressly permitted to: (i) make an
assignment of any or all rights under this Agreement without the other Party's
consent to Affiliates or to an entity that acquires all or substantially all of
the business of such Party, whether in a merger, consolidation, reorganization,
acquisition, sale or otherwise, provided that in any event such assignment shall
be subject to the provisions of Section 4.6 (as applicable) on a
product-by-product basis, and (ii) assign or transfer such rights or obligations
expressly permitted under Sections 4.6, 18.5 and 18.6 without the other Party's
prior written consent. This Agreement shall be binding on the successors and
assigns of the assigning Party, and the name of a Party appearing herein shall
be deemed to include the name(s) of such Party's successors and permitted
assigns to the extent necessary to carry out the intent of this Agreement. Any
assignment or attempted assignment by either Party in violation of the terms of
this Section 18.7 shall be null and void and of no legal effect. The assigning
Party shall forward to the other Party a copy of those portions of each fully
executed assignment agreement which relate to the assumption of the rights and
responsibilities of the assigning Party, within [**] of the execution of such
assignment agreement.

      18.8 COUNTERPARTS. This Agreement may be executed in two (2) or more
counterparts, each of which shall be deemed an original, but all of which
together shall constitute one and the same instrument.

      18.9 SEVERABILITY. If any one or more of the provisions of this Agreement
are held to be invalid or unenforceable by any court of competent jurisdiction
from which no appeal can be or is taken, the provision shall be considered
severed from this Agreement and shall not serve to invalidate any remaining
provisions hereof. The Parties shall make a good faith effort to replace any
invalid or unenforceable provision with a valid and enforceable one such that
the objectives contemplated by the Parties when entering this Agreement, as
evidenced by the terms of this Agreement in accordance with Section 18.18, may
be realized.

      18.10 HEADINGS. The headings for each Article and Section in this
Agreement have been inserted for convenience of reference only and are not
intended to limit or expand on the meaning of the language contained in the
particular Article or Section. Unless otherwise specified, (a) references in
this Agreement to any Article, Section, Exhibit or Schedule shall mean
references to such Article, Section, Exhibit or Schedule of this Agreement, (b)
references in any Section to any clause are references to such clause of such
Section, and (c) references to any agreement, instrument or other document in
this Agreement refer to such agreement, instrument or other document as
originally executed or, if subsequently varied, replaced or supplemented from
time-to-time, as so varied, replaced or supplemented and in effect at the
relevant time of reference thereto.

[**] Portions of this exhibit have been omitted pursuant to a confidential
treatment request. An unredacted version of this exhibit has been filed with the
Commission.
<PAGE>
      18.11 FURTHER ACTIONS. Each Party agrees to execute, acknowledge and
deliver such further instruments and to do all such other acts as may be
necessary or appropriate in order to carry out the purposes and intent of the
Agreement.

      18.12 INDEPENDENT CONTRACTORS. The relationship between ViaCell and Amgen
created by this Agreement is solely that of independent contractors. This
Agreement does not create any agency, distributorship, employee-employer,
partnership, joint venture or similar business relationship between the Parties.
Neither Party is a legal representative of the other Party, and neither Party
can assume or create any obligation, representation, warranty or guarantee,
express or implied, on behalf of the other Party for any purpose whatsoever.
Each Party shall use its own discretion and shall have complete and
authoritative control over its employees and the details of performing its
obligations under this Agreement.

      18.13 NO BENEFIT OF THIRD PARTIES. The representations, warranties,
covenants and agreements set forth in this Agreement are for the sole benefit of
the Parties hereto and their successors and permitted assigns, and they shall
not be construed as conferring any rights on any Third Parties.

      18.14 USE OF NAMES, LOGOS OR SYMBOLS. Except as otherwise explicitly
authorized under this Agreement, no Party hereto shall use, and no rights are
granted in or to, the names or trademarks (including the names "Amgen" and
"ViaCell"), physical likeness, employee names or owner symbol of any other Party
for any purpose (including, without limitation, private or public securities
placements) without the prior written consent of the affected Party, such
consent not to be unreasonably withheld or delayed so long as such use of name
is limited to objective statement of fact rather than for endorsement purposes.

      18.15 NO WAIVER. Any delay in enforcing a Party's rights under this
Agreement or any waiver as to a particular default or other matter shall not
constitute a waiver of such Party's rights to the future enforcement of its
rights under this Agreement, except with respect to an express written and
signed waiver relating to a particular matter for a particular period of time.

      18.16 OFFSET. Either Party shall be entitled to offset, against any
payments due and payable to the other Party hereunder, all such amounts due and
payable hereunder but not yet paid by the other Party to the Party seeking such
offset. Prior to applying an offset under this Section 18.16, the Party seeking
such offset shall first give the other Party written notice of such due and
payable amounts and shall request the other Party to pay all such due and
payable amounts within [**] from the date of such notice.
<PAGE>
      18.17 EXPORT REQUIREMENTS. It is understood and acknowledged that the
transfer of certain commodities and technical data is subject to United States
laws and regulations controlling the export of such commodities and technical
data, including all Export Administration Regulations of the United States
Department of Commerce. Each Party hereby agrees and by entering into this
Agreement gives written assurance that it shall comply with all United States
laws and regulations controlling the export of commodities and technical data
within Information and Materials, that it will be solely responsible for any
violation of any such laws and regulations by itself, its Affiliates or its
sublicensees, and that it will Indemnify, defend and hold the other Party
harmless from any liability in the event of any legal action of any nature
occasioned by such violation, pursuant to Section 15.1 (in the case of Amgen) or
Section 15.2 (in the case of ViaCell).

      18.18 ENTIRE AGREEMENT; AMENDMENT. This Agreement (including all Exhibits
and Schedules) set forth the complete, final and exclusive agreement and all the
covenants, promises, agreements, warranties, representations, conditions and
understandings between the Parties hereto and supersedes and terminates all
prior agreements and understandings between the Parties; on the Effective Date
of this Agreement, the License Agreement dated April 9, 2002 (Amgen Reference
No. 200203067) and all Material Transfer Agreements between the Parties are
hereby superseded, and shall be subject to the terms of, this Agreement. There
are no covenants, promises, agreements, warranties, representations, conditions
or understandings, either oral or written, between the Parties other than as are
set forth herein and therein. This Agreement may only be modified or
supplemented in a writing expressly stated for such purpose and signed by an
authorized officer of each Party (i.e., it may not be modified by any purchase
order, change order, acknowledgment, order acceptance, standard terms of sale,
invoice or the like); except that the JSC may amend or update the Program Plan
as expressly permitted hereby.

      18.19 EXHIBITS AND SCHEDULES. All Exhibits and Schedules referenced herein
and attached hereto are incorporated in this Agreement by reference. In case of
any discrepancies between the language incorporated from the Exhibits and
Schedules and the terms of the Sections, the terms of the Sections shall
prevail; provided however, where Sections of the Agreement make explicit
reference to a substantive matter contained in an Exhibit or Schedule, or with
respect to definitions set forth in the Exhibits or Schedules, the substantive
matter or definitions contained in such Exhibit and Schedules shall prevail.
<PAGE>
      IN WITNESS WHEREOF, the Parties have executed this Agreement in duplicate
originals by their duly authorized representatives as of the Effective Date.

AMGEN INC.                            VIACELL, INC.


By: /s/ Richard A. Namula             By: /s/ Marc Beer

Print Name: Richard A. Namula         Print Name: Marc D. Beer

Title: Executive Vice President       Title: Chief Executive Officer
       Finance Strategy and
       Communications, and
       Chief Financial Officer
<PAGE>
                                    EXHIBIT A

                  AMGEN PATENT RIGHTS AS OF THE EFFECTIVE DATE


[**]


[**] Portions of this exhibit have been omitted pursuant to a confidential
treatment request. An unredacted version of this exhibit has been filed with the
Commission.

                                                                             A-1
<PAGE>
                                    EXHIBIT B

                      ALLOWABLE COLLABORATION EXPENDITURES

                     TO THE OPERATING PROFIT OR LOSS ACCOUNT

This Exhibit B outlines the understanding of the Parties as to how revenues and
expenses will be accounted for after the relevant Transition Date for the
purposes of generating budgets for Development, manufacturing and
Commercialization of each Collaboration Product and for settling accounts
between the Parties.

I.    CALCULATION OF OPERATING PROFIT OR LOSS

            A. The Operating Profit or Loss shall be calculated by subtracting
      from the amount of Net Sales of each Collaboration Product the Allowed
      Expenditures (as defined below) for such Collaboration Product.

            B. In each category of Allowed Expenditures, each Party shall be
      entitled to include the following costs actually incurred, to the extent
      necessary to perform the defined activities within each category of
      Allowed Expenditures: (a) all actual Third Party costs and expenses
      incurred in performing such defined activities, as recognized in
      accordance with GAAP; (b) the Internal FTE Cost of performing such defined
      activities; and (c) the cost of materials used in performing such defined
      activities, provided that costs are not covered in (a) or (b). In any
      event, each Party shall properly account in its books and records for how
      such costs were incurred.

            C. Except as otherwise explicitly set forth in the Agreement or as
      mutually agreed by the Parties prior to incurring a cost or expense, the
      Allowed Expenditures shall include solely costs and expenses incurred
      after the Transition Date for each Collaboration Product.

            D. The Parties shall not charge or include any cost or expense more
      than once or in the calculation of more than one category of Allowed
      Expenditures.

II. CALCULATION OF ALLOWED EXPENSES - "Allowed Expenditures" shall mean
collectively, the Cost of Goods Manufactured, Development Expenditures,
Regulatory Expenditures, Commercial Expenditures and Other Allowed Expenditures,
and shall be calculated in accordance with the this Exhibit B.

            A. "Development Expenditures" shall mean all costs and expenses
      incurred in study design of clinical trials and protocols, contracting
      with clinical sites, recruiting and enrolling patients to participate in
      the clinical trials, collecting and analyzing the clinical trial data,
      incorporating the clinical trial data into appropriate regulatory filings,


[**] Portions of this exhibit have been omitted pursuant to a confidential
treatment request. An unredacted version of this exhibit has been filed with the
Commission.

                                      B-1
<PAGE>
      and otherwise performing clinical trials, but in any event excluding all
      Cost of Goods Manufactured, Regulatory Expenditures, Commercial
      Expenditures and Other Allowed Expenditures.

            B. "Cost of Goods Manufactured" shall mean

                  (i) For Clinical Collaboration Products and Clinical
            Contributed Products, the sum of (a) any royalties or other payments
            payable to a Third Party for the manufacturing of a Clinical
            Collaboration Product and Clinical Contributed Product and (b) the
            Process Development/Manufacturing Expenditures; and

                  (ii) For Commercial Collaboration Products and Commercial
            Contributed Products, the sum of (a) any royalties or other payments
            payable to a Third Party for the manufacturing or sale of a
            Commercial Collaboration Product and Commercial Contributed Product
            and (b) Standard Costs; and

                  (iii) In any event, excluding all Development Expenditures,
            Regulatory Expenditures, Commercial Expenditures and Other Allowed
            Expenditures;

            provided, that Cost of Goods Manufactured may be charged by the
            Party that incurred such costs [**] Expenses incurred for
            manufacture of Commercial Collaboration Products that are [**].
            Expenses incurred for manufacture of Commercial Collaboration
            Products that are [**]. The per-unit cost of Commercial
            Collaboration Products will be calculated pursuant to the terms of
            this Exhibit B and Section 6.4(d) of the Agreement.

            C. "Regulatory Expenditures" shall mean all costs and expenses
      incurred in preparing for and attending regulatory meetings,
      communications, filings and approvals (including any applicable
      governmental price and reimbursement approvals), licenses, registrations,
      or authorizations of any Regulatory Authority necessary for the
      manufacture, use, storage, import, export, transport, Promotion, marketing
      and sale of a Collaboration Product in a country. In any event,
      "Regulatory Expenditures" excludes Cost of Goods Manufactured, Development
      Expenditures, Commercial Expenditures and Other Allowed Expenditures



                                      B-2
<PAGE>
            D. "Commercial Expenditures" shall mean all costs and expenses
      incurred in Advertising and Promotion, Marketing, Market Research, Medical
      Affairs and Detailing. [**]. In any event, "Commercial Expenditures"
      excludes Cost of Goods Manufactured, Development Expenditures, Regulatory
      Expenditures and Other Allowed Expenditures.

            E. "Other Allowed Expenditures" shall mean License Fees, patent and
      trademark prosecution and defense expenses allowed under Article 10 of the
      Agreement, all costs and expenses incurred in performing Recalls described
      in Section 5.10 of the Agreement and transition expenditures permitted
      under Section 4.5 of the Agreement. In any event, "Other Allowed
      Expenditures" excludes Cost of Goods Manufactured, Development
      Expenditures, Regulatory Expenditures and Commercial Expenditures.

III. PRINCIPLES FOR ALLOCATING [**] COST AMONG MULTIPLE PRODUCTS - For the
purposes of allocating the Internal FTE Cost incurred by a Party [**], the
following shall apply in the event [**]. The [**] Internal FTE Cost, the [**]
Internal FTE Cost and the [**] Internal FTE Cost (i.e., [**]).

IV. OTHER DEFINITIONS.

            A. "Advertising and Promotion" shall mean activities necessary for
      (i) the marketing, advertising and Promotion of Collaboration Products
      (including, without limitation, educational expenses, radio, television or
      journal advertising, advocate development programs and symposia, and
      Promotional Materials); (ii) providing free samples of Collaboration
      Product; and (iii) training and communication materials for the
      Collaboration Products.

            B. "Clinical Collaboration Products" shall mean batches of
      Collaboration Product other than Commercial Collaboration Products.

            C. "Clinical Contributed Products" shall mean batches of Contributed
      Product other than Commercial Contributed Products.



                                      B-3
<PAGE>
            D. "Commercial Collaboration Products" shall mean batches of
      Collaboration Products produced in a facility commercially licensed for
      production of such Collaboration Products, the first batches of which
      shall be the conformance lots.

            E. "Commercial Contributed Products" shall mean batches of
      Contributed Products produced in a facility commercially licensed for
      production of such Contributed Products, the first batches of which are
      expected to be the conformance lots. In all events, SCF shall be deemed a
      Commercial Contributed Product.

            F. "FTE" shall mean the amount of labor produced by a full-time
      equivalent person in one year (consisting of at least [**] hours per year)
      performing scientific, technical or management activities. Each party
      shall identify, in the Program Plan, the number and function of FTEs for
      the collaboration, [**].

            G. "FTE Costs" shall mean either the external or internal cost of
      providing a [**] FTE [**] to support the collaboration:

                  (i) External FTE Costs will be charged to the Operating Profit
            or Loss account based on [**]

                  (ii) Internal FTE Costs will be charged to the Operating
            Profit or Loss account based on the number of [**] FTEs performing
            defined activities in accordance with recorded time charges. The
            Parties have agreed to bill these FTEs to the Operating Profit or
            Loss account [**] which shall be deemed to [**]. This rate will be
            [**], based on [**]. Each party shall document this [**] with a copy
            of the relevant portion of the minutes for their respective [**].

            H. "License Fees" shall mean all upfront payments, milestone
      payments, license fees, royalties or other payments, payable to any Third
      Party under any Third Party license agreement for which payments may be
      incorporated pursuant to Section 7.2(e)(ii) of the Agreement.

            I. "Marketing" shall mean marketing communications, sales force
      training, managing corporate accounts, maintaining relationships with
      managed care providers,


                                      B-4
<PAGE>
      providing product and reimbursement support, pricing, conducting
      compassionate use programs for Collaboration Products.

            J. "Market Research" shall mean all qualitative and quantitative
      market research to assess the Collaboration Product's market potential and
      competitive landscape given an expected product profile with specific
      attributes.

            K. "Medical Affairs" shall mean planning, preparing and conducting
      pharmacoeconomics studies, outcomes studies, extramural studies, Phase 3B
      studies and Post Marketing Approval Studies.

            L. "Process Development/Manufacturing Expenditures" shall mean all
      costs and expenses incurred in performing the following activities solely
      relating to production of Clinical Collaboration Products or Clinical
      Contributed Products, [**].

            M. "Standard Costs" shall mean the following costs and expenses
      incurred by the manufacturer of Contributed Products and/or Collaboration
      Products (as applicable), [**].


                                      B-5








<PAGE>
                                    EXHIBIT C

                                COVERED ENTITIES

                                      [**]

[**] Portions of this exhibit have been omitted pursuant to a confidential
treatment request. An unredacted version of this exhibit has been filed with the
Commission.

                                      C-1
<PAGE>
                                    EXHIBIT D

                         ADDITIONAL CONTRIBUTED PRODUCTS

          None.

[**] Portions of this exhibit have been omitted pursuant to a confidential
treatment request. An unredacted version of this exhibit has been filed with the
Commission.

                                       D-1
<PAGE>
                                    EXHIBIT E

                         FLT3 LIGAND AMINO ACID SEQUENCE

Thr Gln Asp Cys Ser Phe Gln His Ser Pro Ile Ser Ser Asp Phe Ala Val Lys Ile Arg
                  5            10            15            20

Glu Leu Ser Asp Tyr Leu Leu Gln Asp Tyr Pro Val Thr Val Ala Ser Asn Leu Gln Asp
                 25            30            35            40

Glu Glu Leu Cys Gly Gly Leu Trp Arg Leu Val Leu Ala Gln Arg Trp Met Glu Arg Leu
                 45            50            55            60

Lys Thr Val Ala Gly Ser Lys Met Gln Gly Leu Leu Glu Arg Val Asn Thr Glu Ile His
                 65            70            75            80

Phe Val Thr Lys Cys Ala Phe Gln Pro Pro Pro Ser Cys Leu Arg Phe Val Gln Thr Asn
                 85            90            95           100

Ile Ser Arg Leu Leu Gln Glu Thr Ser Glu Gln Leu Val Ala Leu Lys Pro Trp Ile Thr
                105           110           115           120

Arg Gln Asn Phe Ser Arg Cys Leu Glu Leu Gln Cys Gln Pro Asp Ser Ser Thr Leu Pro
                125           130           135           140

Pro Pro Trp Ser Pro Arg Pro Leu Glu Ala Thr Ala Pro
                145           150

                                       E-1
<PAGE>
                                    EXHIBIT F

                             SCF AMINO ACID SEQUENCE

                              1                         10
                              E  G  I  C  R  N  R  V  T  N


                          20                            30
N  V  K  D  V  T  K  L  V  A  N  L  P  K  D  Y  M  I  T  L


                          40                            50
K  Y  V  P  G  M  D  V  L  P  S  H  C  W  I  S  E  M  V  V


                          60                            70
Q  L  S  D  S  L  T  D  L  L  D  K  F  S  N  I  S  E  G  L


                          80                            90
S  N  Y  S  I  I  D  K  L  V  N  I  V  D  D  L  V  E  C  V


                         100                           110
K  E  N  S  S  K  D  L  K  K  S  F  K  S  P  E  P  R  L  F


                         120                           130
T  P  E  E  F  F  R  I  F  N  R  S  I  D  A  F  K  D  F  V


                         140                           150
V  A  S  E  T  S  D  C  V  V  S  S  T  L  S  P  E  K  D  S


                         160

R  V  S  V  T  K  P  F  M  L  P  P  V  A  A

                                      F-1
<PAGE>
                                    EXHIBIT G

                              VIACELL PATENT RIGHTS
                 [VIACELL TO UPDATE BASED ON RECENT ACQUISITION]

     [**]


[**] Portions of this exhibit have been omitted pursuant to a confidential
treatment request. An unredacted version of this exhibit has been filed with the
Commission.

                                      G-1
<PAGE>
                                    EXHIBIT H

                               VIACELL TRADEMARKS

<Table>
<Caption>
                               Trademark           Application    Registration
Status         Number:         Name/Description    Date           Date          Registered Use of Mark:                  Owner
<S>            <C>             <C>                 <C>            <C>           <C>                                      <C>
Pending        EC              ViaCell             9/13/2000                    Cellular medicines for the treatment     ViaCell
               1853571                                                          of human disease, namely, cancer,
               (application)                                                    genetic disease, neurologial
                                                                                diseases, infectious diseases, organ
                                                                                transplant tolerance and autoimmune
                                                                                diseases; in Class 5.

Pending        US              ViaCell             4/12/2000                    Cellular medicines for the treatment     ViaCell
               76/024540                                                        of human disease, namely, cancer,
               (application)                                                    genetic disease, neurologial
                                                                                diseases, infectious diseases, organ
                                                                                transplant tolerance and autoimmune
                                                                                diseases; in Class 5.
</Table>
[**] Portions of this exhibit have been omitted pursuant to a confidential
treatment request. An unredacted version of this exhibit has been filed with the
Commission.

                                      H-1